Mononuclear and dinuclear copper(II) complexes [Cu-2(mu-nap)(4)(3-pic)(2)] (1) and [Cu(nap)(2)(H2O)(4-pic)(2)] (2) have been synthesized in the presence of 3-picoline and 4-picoline. Two complexes were characterized by FT-IR, UV-vis spectroscopic methods and their thermal stabilities were determined by TG/DTA/DTG techniques. The crystal structures of 1 and 2 were established by X-ray analysis. X-ray structure analysis has shown that copper(II) has a distorted square-pyramidal geometry. Naproxenate is a bridging ligand in 1 and monodentate in 2. Two complexes have shown catalytic activity on oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations. The complexes were also screened for antimicrobial activity against pathogenic bacteria and fungi. The complexes exhibited antimicrobial activity against Entrococcus faecalis and Candida albicans.