In this research work with an intention of synthesizing some potent antimicrobial agents, we have synthesized two novel series of triazole derivatives (3f-j and 5k-o) and screened them for antibacterial, antifungal, and antitubercular activities. For the synthesis of compounds 3f-j, initially compound (1) was treated with various substituted aromatic aldehydes which results in synthesis of 4-(substituted benzylidenamino)-5-[(naphthalen-4yloxy) methyl]-4H-1,2,4-triazolo-3-thiol (2a-e), further (2a-e) is converted to 2-[4-(substituted benzylidenamino)5-(naphthalen-4-yloxy)methyl-4H-1,2,4-triazol-3-ylthio]acetic acid (3f-j) derivatives by the reaction with chloroacetic acid. Similarly, for the synthesis of titled compounds (5k-o), compound 1 was condensed with isonicotinyl hydrazide to give 2-[4-amino-5-(naphthalen-4-yloxy) methyl-4H-1,2,4-triazol-3-yl] isonicotinyl hydrazide (4) and compound (4) converted to Schiff derivatives of 2-[4-(2- substituted benzylidenamino)-5(naphthalen-4-yloxy) methyl-4H-1,2,4-triazol-3-yl] isonicotinyl hydrazide (5k-o) using substituted aromatic aldehydes. The structures of the synthesized compounds (3f-j and 5k-o) were confirmed on the basis of infrared, nuclear magnetic resonance, and mass spectral data. All the synthesized compounds (3f-j and 5k-o) were screened for their antibacterial, antifungal, and antitubercular activities using broth microdilution method and microplate alamar blue assay method, respectively. Among the synthesized compounds, 3g and 5o showed significant antitubercular activity, compounds 3g, 3j, 5l, and 5o showed significant antibacterial and antifungal activity. [GRAPHICS]