Several new 2,5-disubstituted derivatives of 1,3,4-thiadiazoles containing isomeric pyridyl were obtained from cyclization of corresponding thiosemicarbazides under acidic conditions. The newly synthesized compounds were characterized using different methods of spectroscopy such as IR, 1H-NMR, 13C-NMR, MS and elemental analysis. The minimal inhibitory concentration (MIC) results of screening of some of the synthesized compounds were also reported. Most of the synthesized compounds have been found to be active against both Gram-positive and Gram-negative bacteria at less than 3.6 mg/ml. The compound (10b) is most active against all seventeen used gram-positive and gram-negative bacteria.