Two series of sulfonamides were synthesized from 4-hydrazinyl­ben­zenesulfonamide as the key starting material. 1,3,5-Tri­arylpyrazoline sulfon­amides (2a–i) were obtained by cyclocondensation of various chalcones in 53–64 % yields, while 4-thiazolidinone derivatives (4a–e) were synthesized by cyclocondensation between mercaptoacetic acid and different phenylhydra­zones in 43–62 % yields. The synthesized compounds were characterized based on FTIR, 1H-NMR, 13C-NMR and HRMS data. The sulfonamides were evaluated for their in vitro antimicrobial activities against four bacterial strains (E. coli, P. aeruginosa, B. subtillis and S aureus), two filamentous fungal strains (A. niger and F. oxysporum) and two yeast strains (C. albicans and S. cerevisiae). Seven pyrazolines, 2a–c and 2e–h, exhibited significant inhibition of different microbial strains. Among them, compound 2b displayed good anti­fungal activity against A. niger (MIC value at 12.5 mg mL-1) over the reference drug.