In the present study we have made an attempt to synthesize substituted 4,5-dihydro-3-(naphthalene-6-yl)-5-phenyl pyrazole carbothioamide derivatives (2a-i) and evaluate them for anti-inflammatory activity using carrageenan induced rat paw edema model. In the first step, 2-acetylnaphthalene (1) was allowed to react with substituted benzaldehyde (2) in equimolar amount with sodium hydroxide to form various substituted derivatives (1a-i). Further substituted chalcone derivatives on treatment with thiosemicarbazide in the presence of ethanol corresponding substituted 4,5-dihydro-3-(naphthalene-6-yl)-5-phenyl pyrazole carbothioamide (2a-i). The structure of the final analogues has been confirmed on the basis of elemental analysis, Fourier Transform Infrared (FTIR), Proton Nuclear Magnetic Resonance (1H-NMR). All the values of elemental analysis, FTIR, 1H-NMR were found to be prominent. Among all synthesized compounds for anti-inflammatory activity compounds 2d and 2h were found to be most potent in comparison with standard diclofenac.