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 SCHWEIZERHALL HOLDING BENELUX B.V. The Netherlands ACETO FRANCE S.A.S. France ACETO PHARMA GmbH - India India ACETO PTE LTD. Singapore ACETO (HONG KONG) LTD. Hong Kong INTERNATIONAL PHARMACEUTICAL CHEMICALS The Netherlands 48