A series of fifteen 1, 3, 4-oxadiazoles derived from 2-hydroxy benzothiazole have been synthesized and screened for the anticancer activity. Different aromatic acids were used for this library for generating structure activity relationship. The in vitro cytotoxicity was done against MCF-7 breast cancer cells. The synthesized compounds showed variable cytotoxic effects. Four compounds showed potent cytotoxic effect with IC50 varies from 1.8µM/mL to 4.5µM/mL. Other compounds showed moderate to lower cytotoxicity. 2-(5-((benzo[d]thiazol-2-yloxy)-methyl)-1,3,4-oxadiazol-2-yl)phenol was the most potent compound which showed a cytotoxicity effect (IC50 1.8 ± 0.02 µM/mL) comparable to the standard drug Doxirubicin (IC50 1.2 ± 0.005 µM/mL). From the result it was observed that aromatic ring activating groups such as methyl and hydroxyl, enhances the cytotoxicity effect, whereas aromatic ring deactivating groups such as nitro group showed moderate cytotoxicity against MCF-7 breast cancer cell line.