Pacific Rim Mining Corp.

Pacific Rim Mining Corp.

March 27, 2006 10:54 ET

Pacific Rim Mining Corp.: South Minita Delineation Drilling Yields Additional High Grade Gold; Updated Resource Calculation Initiated

VANCOUVER, BRITISH COLUMBIA--(CCNMatthews - March 27, 2006) - Pacific Rim Mining Corp.'s ("Pacific Rim" or "the Company") (TSX:PMU)(AMEX:PMU) South Minita definition drilling program on the El Dorado project, El Salvador, has yielded additional high grade gold intersections from both step out and infill holes, including 19.26 g/t gold over 2.75 meters and 44.98 g/t gold over 1.1 meters.

The latest results from the South Minita drilling further expand and better define the three parallel veins that comprise this gold zone. Barring the near-term discovery of any new mineralized areas in the Minita - South Minita corridor that would necessitate further follow-up drilling, the Company anticipates imminently commencing an updated resource calculation to include the South Minita deposit in the El Dorado reserve and resource base. The results of the updated resource estimate are currently expected to be available by June 2006.

Latest South Minita Drill Results

UTM azi- From To Inter- True
Vein North- muth/ (met- (met- sec- Wid-
or ing/ dip ers ers tion th Sil-
Hole System East- (degr- down down met- (met- Gold ver
No. Tested ing ees) hole) hole) ers) ers) (g/t) (g/t)
(i) Minita 301460/ 112/ No significant results
533977 67
(i) Minita 301482/ 90/ 247.00 248.55 1.55 1.10 44.98 302
534057 75 256.40 256.60 0.20 0.15 20.20 218
265.75 266.70 0.95 0.65 6.75 39
345.70 351.25 5.55 2.10 6.42 9
394.80 396.15 1.35 1.10 6.68 19
(i) Minita 301727/ 90/ 433.45 434.45 1.00 0.65 8.86 114
533870 68
P05-412 South 300514/ 273/ 346.90 347.25 0.35 0.30 64.25 414
Minita 534393 60 409.95 410.45 0.50 0.40 7.42 42
440.70 441.00 1.70 1.10 4.52 20
P05-413 South 299975/ 270/ 412.10 413.10 1.00 1.00 11.66 66
Minita 534426 53 425.50 426.75 1.25 1.05 13.59 106
P06-414 Minita 301723/ 113/ No significant results
533869 68
P06-415 South 300449/ 270/ No significant results
Minita 534294 64
P06-416 South 300078/ 254/ Results pending
Minita 534335 59
P06-417 South 300493/ 270/ 469.45 469.70 0.25 0.20 10.21 n.a.
Minita 534300 76
P06-418 South 300813/ 260/ 515.10 515.55 0.45 0.35 7.31 102
Minita 534444 58
P06-419 South 299972/ 271/ No significant results
Minita 534411 60
P06-420 South 534309/ 266/ 240.80 241.40 0.60 0.60 11.72 n.a.
Minita 300548 61 263.30 264.10 0.80 0.80 6.13 31
344.40 345.40 1.00 0.80 8.91 67
P06-421 South 300240/ 270/ 295.95 299.35 3.40 2.75 19.26 135
Minita 534388 60 361.00 362.40 1.40 1.10 7.01 49
364.40 365.70 1.30 1.30 5.56 38
374.25 376.95 2.70 2.40 8.69 105
P06-422 South 299904/ 272/ No significant results
Minita 534384 65
P06-423 South 300606/ 259/ 393.10 394.55 1.45 1.35 27.87 200
Minita 534331 65
P06-424 South 300045/ 268/ No significant results
Minita 534503 65
P06-425 South 300240/ 270/ 291.50 293.15 1.65 1.30 15.62 82
Minita 534388 53
including 292.80 293.15 0.35 0.25 59.62 200

(i) updates results pending from news release #06-02 dated
January 24, 2006.

Exploration Update

Pacific Rim's exploration emphasis over the past year and a half has been to expand and develop the El Dorado mine proposed in the Company's January 2005 pre-feasibility study through the addition of new gold mineralization at South Minita and the continuation of the Company's ongoing pre-construction development work. This strategy will continue through 2006 with the calculation of a new resource estimate for the El Dorado project, the completion of a feasibility study to examine the economics of an expanded operation at the Minita - South Minita deposit, and, upon receipt of a mining permit, the commencement of underground ramp construction.

Upon completion of the South Minita delineation drill program, Pacific Rim's exploration focus will resume testing for new high-grade vein-hosted gold mineralization amongst the myriad of excellent drill ready targets the Company has discovered over the past year and a half at both the El Dorado and nearby Santa Rita projects.

"Since discovering the South Minita gold mineralization over a year ago, we have been working hard to delineate this complex deposit so that we could demonstrate the upside economic benefit that these gold ounces offer to the proposed El Dorado mine," says Tom Shrake, CEO. "We believe South Minita has the potential to significantly increase the annual production rate for the El Dorado mine and help us reach our goal of becoming a low-cost, intermediate level gold producer, and we look forward to reaching these important milestones in the coming months. After 15 months of focusing our drilling on resource definition, we will soon be employing our drill fleet (recently expanded to 4 rigs) on the more exciting process of exploration drilling for new deposits."

NI 43-101 Disclosure

Pacific Rim's exploration work on the El Dorado project is supervised by William Gehlen a Certified Professional Geologist with the AIPG (No. 10626), an employee of Pacific Rim and a Qualified Person as defined in NI 43-101. Mr. Gehlen has verified that the drill results presented above have been accurately summarized from the official assay certificates provided to the Company. Pacific Rim's drill sampling procedures follow the Exploration Best Practices Guidelines outlined by the Mining Standards Task Force and adopted by The Toronto Stock Exchange. Samples have been assayed using fire assay with a gravimetric finish on a 30-gram split. Quality control measures, including check- and sample standard-assaying, are being implemented. Samples were assayed by Inspectorate America Corporation in Reno, Nevada USA, an ISO 9002 certified laboratory, independent of Pacific Rim Mining Corp.

The Minita pre-feasibility study is supported by a technical report prepared for Pacific Rim Mining Corp. by SRK Consulting (US) Inc. of Denver Colorado, entitled "Pre-Feasibility Study, El Dorado Project, El Salvador", dated January 21, 2005 and publicly available on SEDAR. The primary author of the report is Mr. William F. Tanaka, a Qualified Person independent of Pacific Rim, as defined in National Instrument 43-101. Mr. Tanaka is a member of the Society of Mining Engineers (SME) and the Australasian Institute of Mining and Metallurgy (mAUSIMM).

About Pacific Rim Mining Corp.

Pacific Rim is a growth-oriented, revenue-generating, environmentally and socially responsible gold exploration company with operational and exploration assets in North, Central and South America. Pacific Rim utilizes the cash flow from its 49% interest in the Denton-Rawhide gold mine in Nevada to explore, define and advance its projects, including the flagship El Dorado gold project in El Salvador. Pacific Rim's goal is to become a highly profitable, intermediate-level gold producer.

On behalf of the board of directors,

Thomas C. Shrake, President and CEO

Cautionary Note Regarding Forward-Looking Information -- Information set forth in this document includes forward-looking statements. By their nature, forward-looking statements are subject to numerous risks and uncertainties, some of which are beyond Pacific Rim's control, including but not limited to: statements of the Minita deposit's economic potential; information included in the pre-feasibility study such as capital and operating costs, projected production summaries, gold and silver prices and financial analysis; anticipated drilling plans for the South Minita gold zone; the timing of a resource estimate for the South Minita gold zone; the impact of the South Minita gold zone on the project's economics; the timing and nature of economic analyses at the El Dorado project; the execution and outcome of current or future exploration activities; significant fluctuations in metal prices; general market and industry conditions; and other factors detailed in the Company's filings with Canadian regulatory agencies and the U.S. Securities and Exchange Commission.

Readers are cautioned that the assumptions used in the preparation of such information, although considered reasonable at the time of preparation, may prove to be imprecise and, as such, undue reliance should not be placed on forward-looking statements. Pacific Rim's actual results, programs and financial position could differ materially from those expressed in or implied by these forward-looking statements.

Cautionary Note to U.S. Investors -- The United States Securities and Exchange Commission permits U.S. mining companies, in their filings with the SEC, to disclose only those mineral deposits that a company can economically and legally extract or produce. This news release may include such terms as "measured," "indicated," and "inferred" "resources" that the SEC guidelines strictly prohibit U.S. registered companies from including in their filings with the SEC. U.S. Investors are urged to consider closely the disclosure in our Form 20-F, File No. 001-31328, which may be secured from us, or from the SEC's website at

The TSX and the AMEX have neither reviewed nor accept responsibility for the adequacy or accuracy of this release.

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