A number of novel thiadiazoles, and triazoles condensed and noncondensed (I-VIII) were obtained from the available and inexpensive fatty acid (stearic acid ). Reaction of stearic acid with thiosemicarbazide in phosphorous oxychloride (POCl3) produced 2-amino-5-heptadecyl-1,3,4- thiadiazole (I), which was utilized to synthesis of condensed thiadiazole (IV, VII, and VIII) and non-condensed (V, VI). Also, thiadiazole reacts with 4-aminobenzoic acid and 2-amino pyridine produced triazolo derivatives (II, and III). Some of the synthesized compounds investigated for their antibacterial, and antifungal activities, and some showed moderate activities, the others showed high antimicrobial activity against various tested bacterial and fungal strains. The surface active properties and biodegradability of some of the synthesized compounds are also evaluated.