The purpose of this open study was to find out whether botulinum toxin A (BTX-A) relieves the signs and symptoms of chronic limb spasticity. The study comprised 40 patients, aged 12-82 years, with moderate to severe spasticity of the upper (13) or lower limbs (27) refractory to conventional physical and medical treatments. Outcome measures were clinical and blinded videotape assessments of spasticity and motor function. Electromyography guided BTX-A injections were given in one or two sessions at total doses averaging 175 U in the upper limb (range 70-270 U) and 221 U in the lower limb (range 100-500 U). Thirty four patients (85%) derived worthwhile benefit, with improved limb posture and increased range of passive motion in 31, pain reduction in 28 of 31 with pain, and improved function in 16. Side effects were limited to local and usually mild discomfort from the injections (19), symptomatic local weakness (one), and local infection (one). Preliminary experience indicates that BTX-A is a promising adjunctive treatment for selected patients with spasticity.