After an initial patient with cerebral palsy had an apparent dramatic reduction in spasticity when placed on modafinil, a pilot study was undertaken in 10 pediatric patients to confirm or refute the benefit of modafinil in cerebral palsy. Nine of 10 patients completed the 1-month treatment period. The study patients were treated with 50 or 100 mg of modafinil once daily in the morning. An assessment was made at baseline and at 1 month on treatment. All patients had a clinical examination, Modified Ashworth Scale scores (spasticity) determined by a physical therapist, and videotaping of ambulation. In comparing visit 1 (baseline) and visit 2 (on treatment), statistically significant improvement in the modified Ashworth Scale scores was noted in seven of the nine patients completing the study (P = .0080). A blinded review of the videotapes did not show statistically significant differences in ambulation, but the speed (ft/sec) of gait improved in six of the nine patients (P = .0192). In this study, modafinil, a newly released central stimulant for narcolepsy, showed benefit in treating spasticity in patients with cerebral palsy. A second larger, placebo-controlled, double-blinded trial is planned to confirm these initial results and observations. Modafinil appears to benefit spastic cerebral palsy by a yet to be determined mechanism; however, a primary effect of modafinil on brainstem structures is hypothesized to reduce spasticity of central origin.