Three new series of 1,3,4-oxadiazole derivatives such as 2-[3-(6-methylpyridinyl)]-5-aryl-[1,3,4]-oxadiazole (3a-e), 2-[3-(6-methylpyridinyl)]-4-substitutedaminomethyl-[1,3,4]-oxadiazole-5-thione (5a-e) and 2-[3-(6-methyl pyridinyl)]-5-substituted benzylthio-[1,3,4]-oxadiazole (6a-e) were synthesized. Newly synthesized compounds were characterized by spectral and analytical studies. All the synthesized compounds were screened for their antidiabetic and antioxidant activity. The Mannich bases (5a-e) showed significant antioxidant activity comparable with that of the standard employed. Compounds 3d and 5a are showing good α-amylase inhibition activity and α- glucosidase inhibition activity against the standard.