The aim of the present study was to find out whether the classic neuroleptic fluphenazine is a good model compound for inducing parkinsonian-like muscle rigidity in rats. The muscle tone was measured as resistance developed by the rat's hind foot to passive flexion and extension. Fluphenazine in doses of 0.4-3.0 mg/kg i.p. induced a dose-dependent increase in the hind foot resistance to passive movements. The muscle rigidity induced by fluphenazine 1.5 mg/kg i.p.) was counteracted in a dose-dependent manner by the main antiparkinsonian drug L-DOPA (25-75 mg/kg i.p.). The present results suggest that the fluphenazine-induced muscle rigidity may be a useful model of parkinsonian rigidity.