A new series of 1′-(4-chlorophenyl)-5-(substituted aryl)-3′-(substituted aryl)-3,4-dihydro-2H,1′H-[3,4′]bipyrazolyl derivatives (6a–e, 8a–e, 10a–e) have been synthesized, characterized and screened for antimicrobial and antitubercular activity. Among the synthesized compounds, the minimum inhibition concentration of 10e was found to be as low as 1.56 μg ml⁻¹ and that of 10c was 6.25 μg ml⁻¹ as compared to the standard anti-tb drugs pyrazinamide and streptomycin.