In continuation of our search for pharmaceutically active heterocyclic compounds we undertook the synthesis of 7-chloro-2-[3-(4-chlorophenyl)-5-aryl-4,5-dihydro-1H-pyrazol-1-yl]-6-fluro-1,3-benzothiazoles (5) and 7-chloro-2-[3-(4-chlorophenyl)-5-aryl-1H-pyrazol-1-yl]-6-fluoro-1,3-benzothiazoles (6). The required 2-hydrazinobenzothiazole (3) was prepared by the action of 2-amino-7-chloro-6-fluro benzothiazole and hydrazine hydrate. Different chalcones (4a-h) have been obtained by the condensation of substituted benzaldehydes with p-chloroacetophenone which were then treated with (3) to obtain corresponding 7-chloro-2-[3-(4-chlorophenyl)-5aryl-4,5-dihydro-1H-pyrazol-1-yl]-6-fluoro-1,3-benzothiazoles (5a-h). The compounds 5 were then converted into 7-chloro-2-[5-aryl-3-(4-chlorophenyl)-1H-pyrazol-1-yl]-6-fluro-1,3-benzothia-zoles (6a-h) by treating with Iodobenzene diacetate in dichloromethane at room temperature. All the compounds synthesized were characterized by spectral data. All the new compounds were screened for anti-inflammatory activity (in vitro model), analgesic activity by tail-flick method, antibacterial activity by the agar diffusion and by MIC methods and antifungal activity.