Exhibit 15.1 November 8, 2006 Aceto Corporation Lake Success, New York We are aware that Aceto Corporation and subsidiaries has incorporated by reference in its Registration Statements on Form S-8 (No. 33-38679, No. 333-90929, and No. 333-110653) our report dated November 8, 2006, relating to the Company's unaudited interim consolidated financial statements appearing in its quarterly report on Form 10-Q for the quarter ended September 30, 2006. Pursuant to Regulation C under the Securities Act of 1933, that report is not considered a part of the registration statement prepared or certified by our firm or a report prepared or certified by our firm within the meaning of Sections 7 and 11 of the Act. It should be noted that we have not performed any procedures subsequent to November 8, 2006. /s/ BDO SEIDMAN LLP Melville, New York