A series of 3-styryl-1, 5-diphenyl and 5-styryl-1, 3-diphenyl 2-pyrazolines of different substitutions has been synthesized by condensation of substituted α, β-unsaturated ketones with phenylhydrazine hydrochloride in presence of catalytic amount of concentrated HCl. Compounds in the 3-styryl series had OMe, NMe₂, NO₂, OH and isopropyl substituents and those in the 5-styryl series had OMe, NMe₂ and NO_s. The 3-styryl-1, 5-diphenyl compounds showed little variation in antibacterial activity towards gram-positive and gram-negative bacteria in terms of geometric mean minimum inhibitory concentrations (MIC). The 4', 4''-NMe₂, 4', 4''-NO₂ and 4', 4''-OMe compounds were found to possess the highest activity in the series. The 5-styryl-1, 3-diphenyl series showed lower activities than the 3-styryl series. The in vitro antimycotic activity of the 4', 4''-OH and 2', 2''-OH substituted compounds showed good activity than the other molecules in the two series.