In an effort to study the effect of 1,3,4-thidiazole based molecules on bacteria, fungal and tuberculosis species, we synthesized a series of Schiff bases (2a-2m) by reacting a variety of carbonyl compounds with 5-amino-1,3,4- thiadiazole-2-thiol. Molecular structure of these compounds was retrieved by spectral methods and elemental analysis. All these compounds were evaluated for their antibacterial, antifungal and antitubercular activities employing standard biological protocols. The compounds 2m and 2l substituted with the electron withdrawing fluorine and nitro groups showed excellent inhibitory activity against Staphylococcus aureus, Aspergillus niger and Candida tropicalis with an MIC of 8 µg/mL whereas 2i containing the electron releasing dimethylamino group showed potent activity against Proteus vulgaris. Additionally, 2m along with 2j, 2k and 2l also exhibited superior antimycobacterial activity than the standard pyrazinamide. The activity data for these compounds pave the way for the development of new antimicrobial and antitubercular drugs.