Clinical signs and symptoms of spasticity include hypertonia, involuntary movements (spasms, clonus), decreased range of motion, contractures, and often spasm-related pain. When spasticity is refractory to medical management, patients may be referred for intrathecal baclofen (ITB) pump placement. We reviewed a cohort of amyotrophic lateral sclerosis (ALS) patients with intractable spasticity requiring ITB to further define the impact of ITB on pain relief in this patient population. From 2003 to 2005, eight patients (mean age 43.8 years; 5 men, 3 women) with ALS received ITB for pain associated with intractable spasticity at our institution. Mean disease duration preoperatively was 47.4 months, mean follow-up was 9.8 months, and pain was evaluated using a 0-10 scoring system. All patients experienced spasticity relief in response to a preoperative bolus test injection of ITB (25-50 microg) via lumbar puncture. Following ITB pump placement, the average reduction of pain was 54% (P = 0.0082). Six patients (75%) experienced pain score reduction, three of whom had complete pain relief. Postoperative pain reduction was predicted by the degree of pain reduction following preoperative ITB test injection. These results support ITB as a treatment modality for pain associated with spasticity in ALS.