Exhibit 16.1 August 11, 2006 U.S. Securities and Exchange Commission Office of the Chief Accountant 100 F Street, NE Washington DC 20549 Re: Pharma-Bio Serv, Inc. File No. 0-50956 Dear Sir or Madam: We have read Item 4.01 of Form 8-K of Pharma-Bio Serv, Inc. dated July 28, 2006, and agree with the statements concerning our Firm contained therein. Very truly yours, s/ Kevane Soto Pasarell Grant Thornton LLP /MLM July 28, 2006 Mr. Howard Spindel Audit Committee Chairman Pharma-Bio Serv, Inc. 373 Mendez Vigo Suite 110 Dorado, PR 00646 Dear Mr. Spindel: This is to confirm that the client-auditor relationship between Pharma-Bio Serv, Inc. (U.S. Securities and Exchange Commission File No.0-50956) and Kevane Soto Pasarell Grant Thornton LLP will cease as of the completion of the third quarter interim review. Very truly yours, s/ Kevane Soto Pasarell Grant Thornton LLP Cc: Office of the Chief Accountant PCAOB Letter File U.S. Securities and Exchange Commission 100 F Street, NE Washington DC 20549