Synthesis and analgesic activity of 4-phenylpiperidine derivatives is a topic of high actuality. A s part of a programme towards obtaining new potential analgesics, ten derivatives of 4- acetyl-4-phenylpiperidine and ten derivatives of 4-hydroxy-4-phenylpiperidine were synthesised and characterized through spectroscopic techniques. All derivatives along with the parent compounds were evaluated for analgesic activity in the acetic acid-induced writhing assay and tail-flick test in mice. All derivatives of 4-acetyl-4-phenylpiperidine except one com pound exhibited more or less protection against mice writhing, whereas all the compounds proved to be inactive in the tail-flick test at doses of 50 and 100 mg/kg body weight.