The 3-[1-(3-benzoylphenyl)ethyl]-1H-isochromen-1-one, 2 and their thio-analogues 3-[1-(3-benzoylphenyl)ethyl]-1H-isochromen-1-thione, 3 and 3-{1-[3-(benzothioyl) phenyl]ethyl}-1H-isochromen-1-one, 5 were successfully obtained in good yield and purity from anti-inflammatory drug ketoprofen, 1 and its thio analogue, 4. The compounds were successfully characterized by FT-IR, MASS, 1HNMR and 13CNMR spectral techniques. The in vitro anti-inflammatory and anti-oxidant screening revealed that 3-[1-(3- benzoylphenyl) ethyl]-1H-isochromen-1-one, 2 possesses better anti-oxidant and anti-inflammatory activity whereas 3-(1-(3-benzoylphenyl)ethyl)-1H-isochromene- 1-thione, 3 and 3-(1-(3-benzothioyl) phenyl] ethyl