In this paper we have studied the effects of morphine, codeine, fentanyl, pentazocine, etorphine and fluphenazine (all drugs injected i.p.) on stereotyped behaviour induced by methylphenidate 60 mg/kg i.p., as well as induced by apomorphine 5 mg/kg s.c. in mice. It was found that all used analgesics and fluphenazine dose--dependently inhibited the intensity of methylphenidate--induced gnawing in mice. This effect of analgesics, but not that of fluphenazine was antagonized by naloxone (0.8 mg/kg i.p.) and nalorphine (10 mg/kg i.p.). Climbing behaviour induced by apomorphine was not reduced by narcotic analgesics, but fluphenazine inhibited this effect dose--dependently. These findings give the behavioural support that analgesics applied have antidopaminergic activity in mice.