Exhibit 21 SUBSIDIARIES OF ACETO CORPORATION State or other jurisdiction of Subsidiary corporation or organization ACCI REALTY CORP. New York ACETO AGRICULTURAL CHEMICALS CORPORATION New York ACETO INDUSTRIAL CHEMICAL CORP. New York ARSYNCO, INC. New Jersey LARLABS, INC. New York ROEHR CHEMICALS, INC. New York CDC PRODUCTS CORP. New York MAGNUM RESEARCH CORP. New York ACETO HOLDING GmbH Germany ACETO PHARMA GmbH Germany ACETO FINE CHEM GmbH Germany ACETO (Holding) B.V. The Netherlands INTERNATIONAL PHARMACEUTICAL CHEMICALS The Netherlands HOLDING B.V. INTERNATIONAL PHARMACEUTICAL CHEMICALS The Netherlands ACETO FRANCE S.A.S. France ACETO LTD. Bermuda ACETO PHARMA GmbH - India India ACETO PTE LTD. Singapore ACETO (HONG KONG) LTD. Hong Kong ACETO SHANGHAI LTD. China 50