A new series of some pyridine condensed oxadiazole derivatives were prepared by reacting pyridine derivative with various aromatic carboxylic acids. In the present work 9 different 2, 5-disubstituted 1, 3, 4 oxadiazole derivatives (3a-i) were synthesized. Pyridine 4-carboxylic acid (Nicotinic acid) is converted into methyl pyridine 4-carboxlate by esterification. Pyridine 4-carboxlate is converted to pyridine 4-carbohydrazide (Isoniazid) by treating with hydrazine hydrate. Pyridine 4-carbohydrazide is converted to 2, 5-disubstituted 1, 3, 4 oxadiazole derivatives by treating with different types of aromatic carboxylic acids in the presence of POCl3. Confirmation of the chemical structure of the synthesized compounds was substantiated by TLC, IR, 1H NMR, and MS spectroscopy.All the synthesized compounds were tested for in-vitro antibacterial (against Escherichia coli, Bacillus subtilis, Staphylococcus aureus) and antifungal activity (against Aspergillus niger). 5e, 5i, 5b, 5d showed better inhibition as compared to the standard Ciprofloxacin and 5b, 5d, 5e & 5i showed good inhibition as compared to the standard Ketokonazole.