Behavioral effects of methyl angolensate were investigated in mice and rats. Spontaneous motor activity, pentobarbital sleeping time, amphetamine-stereotyped behaviour, exploratory activity and apomorphine-induced climbing studies in mice were evaluated. The results revealed that methyl angolensate reduced spontaneous motor activity in mice, prolonged the duration of pentobarbital sleeping time in rats and attenuated amphetamine-induced stereotype behaviour in rats. Methyl angolensate also decreased exploratory activity in mice and reduced the rate of apomorphine-induced climbing in mice at the doses tested. It is suggested that methyl angolensate possesses some biologically active principles that are sedative in nature.