N-phenyl-5-substituted aryl-3-p-(fluorophenyl) pyrazoles have been synthesized from cyclization of 4-fluoroacetophenone (1) with various benzaldehydes (2) to give 4fluorophenylsterylketone (3) followed by treatment with phenyl hydrazine. The title compounds and their derivatives have been characterized by their elemental and spectral analysis. The newly synthesized compounds are screened for anti-bacterial activity. A few of the compounds gave promising results.