Seven alkylthiosulfates and three diaryl thiosulfates were synthesized as potential antineoplastic agents, and subjected to antineoplastic activity test against Ehrlich ascites carcinoma, SN-36 Leukemia and Sarcoma 180. Allyl thiosulfate, n-propylthiosulfate and ${eta}$-hydroxyethylthiosulfate were found as to be active against experimental tumors.