Lisuride was reported as drug stimulating sexual behaviour in the adult male rats. It was stated that lisuride is effective through central serotonergic and dopaminergic systems. The present study deals with the effects of lisuride on the sexual behaviour of juvenile Wistar male rats, 43 days old. The animals were injected i.p. with lisuride /0.4 mg/kg/ or saline 40 min prior to testing. When the males were put into a box with the floor prescented by an oestrous female, the males treated with lisuride devoted significantly more time to the sniffing of the scent traces. After a darting female was placed into the box, some of the lisuride injected males initiated copulatory behaviour, even without previous precopulatory behaviour towards her. In noncopulating males treated with lisuride the frequency of precopulatory activities was comparable with those seen in the controls, but the predominance of precopulatory touching the flanks over anogenital exploration was suggested. The results are related to those acquired in the adult animals.