Several 3-(β-picolinoylaminoazo methyl-5-aromatic substituted)-1-thioamide-2-pyrazoline derivatives (4a-4e) were synthesized by reacting substituted 1-(β-picolinoylaminoazo)-3- benzylidene propan-2-one derivatives (3a-3e) with thiosemicarbazide in ethanol. The structures of the synthesized compounds were confirmed by FTIR, 1H NMR, and EIMS spectral data. Their antimicrobial activities against E. coli (MTCC 442), P. Aeruginosa (MTCC 441), S. Aureus (MTCC 96), S. Pyrogenus (MTCC443) were investigated. A significant level of activity was observed.