Thirty-seven patients with spasmodic torticollis (cervical dystonia) who received repeated local injections of botulinum toxin have been followed up for a mean period of 12.3 (10-29) months, during which time 138 treatment sessions were performed. Mean doses per muscle averaged 320 mouse units (mu; range 160-1000 mu botulinum toxin A prepared by CAMR, Porton Down, UK). Eighty-six per cent of patients experienced significant improvement of posture and 84% of those with pain had relief following the first injection. Muscular patterns of recurrent torticollis were relatively constant and in most patients efficacy was maintained with subsequent injections, while 15% of all follow-up sessions failed. Only 2 of 37 patients were consistent nonresponders; 22% and 10% of all sessions were complicated by transient dysphagia and weakness of neck muscles, respectively. It is concluded that local botulinum toxin injections can be a safe and efficaceous long-term treatment of spasmodic torticollis and that optimal doses should be between 200 and 400 mu/muscle.