Neuroleptic-induced tardive dyskinesia (TD) is a motor disorder of the orofacial region resulting from chronic neuroleptic treatment. The agents improving dopaminergic transmission improve TD. Mucuna pruriens seed contains levodopa and amino acids. The effect of methanolic extract of M. pruriens seeds (MEMP) was studied on haloperidol-induced TD, alongside the changes in lipid peroxidation, reduced glutathione, superoxide dismutase (SOD) and catalase levels. The effect of MEMP was also evaluated in terms of the generation of hydroxyl and 1,1-diphenyl,2-picrylhydrazyl (DPPH) radical. MEMP (100 and 200 mg kg⁻¹) inhibited haloperidol-induced vacuous chewing movements, orofacial bursts and biochemical changes. MEMP also inhibited hydroxyl radical generation and DPPH. The results of the present study suggest that MEMP by virtue of its free radical scavenging activity prevents neuroleptic-induced TD.