Moxiraprine (also known as CM-30366) is aminopyridazine derivative with antidepressant activity. In preclinical studies Moxiraprine induced stereotyped behaviour and antagonized haloperidol-induced catalepsy in rats, after parenteral and oral administration. In 6-hydroxy dopamine (6-OHDA)-lesioned mice, Moxiraprine induced contralateral rotations and, when injected before 6-OHDA, protected mice against its neurotoxicity. Moxiraprine also provoked contralateral rotations when injected directly into the mouse right striatum. After parenteral injection, Moxiraprine slightly increased motility in mice, at least at low doses. The stereotypies and rotations (after intrastriatal injection) induced by Moxiraprine were antagonized by haloperidol, alpha-methyl-p-tyrosine and reserpine. The effects of Moxiraprine were compared to those of direct and indirect dopamine-like drugs. Bromocriptine induced a behavioural profile, which in most aspects, was qualitatively and quantitatively similar to that of Moxiraprine. Apomorphine was found slightly more potent than Moxiraprine, but in contrast to the latter, apomorphine-induced stereotypies were insensitive to alpha-methyl-p-tyrosine or reserpine. (+)-Amphetamine and nomifensine were less potent than Moxiraprine, and unlike Moxiraprine, induced ipsilateral rotations in 6-OHDA-lesioned mice.