This case report presents a patient with tardive dyskinesia who also suffered from masticatory muscle pain and temporomandibular joint osteoarthrosis. The patient was treated with clozapine in gradually increasing doses and two injections of botulinum toxin type A one year apart. Involuntary movements of mandibular clenching and bruxing disappeared and pain was relieved to a great extent. Reappearances of dyskinetic movements and pain were observed during the follow-up period of 1.5 years. Keywords: antipsychotic, botulinum toxin type A, clozapine, tardive dyskinesia, temporomandibular disorder