A series of 3-(2-substitutedphenyl)-1-(6-methoxy-1,3-benzothiazol-2-yl)-1H-pyrazole-4-carbaldehyde derivatives (5a-g) were synthesized in satisfactory yield and were evaluated for their antimicrobial activity. All the synthesized compounds were evaluated for their in vitro antibacterial activities against four pathogenic bacterial strains, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and two fungal strains Aspergillus niger and Candida albicans by disc diffusion method. The antibacterial activities were expressed as minimum inhibitory concentration (MIC) in 100 μg/ml. The compounds have shown moderate activity. Compounds 5e, 5f, 5g were found to be most active. Other compounds were shown moderate activity. All the synthesized compounds were in good agreement with elemental and spectral data (FT-IR, 1HNMR and mass spectroscopy).