The present study examines the influence of dexamethasone on the behavioural effects induced by baclofen in mice. The behaviour elements considered were locomotor activity, motor co-ordination, catalepsy, stereotyped behaviour and antinociception. Baclofen (1.0-4.0-6.0 mg kg-1, i.p.) induced a significant reduction of all behavioural elements studied and an antinociceptive effect was recorded. Dexamethasone alone (0.1-0.5-1.0 mg kg-1, i.p.) did not induce significant changes in the behaviour elements considered. On the other hand, when the steroid was injected immediately before baclofen a significant reduction of baclofen's behavioural effects was found. Our results suggest a possible link between glucocorticoid and the GABA-ergic system.