The purpose of this study was to determine whether electrical stimulation of the gluteus maximus would improve hip extensor strength, decrease excessive passive and dynamic internal hip rotation, and improve gross motor function in children with cerebral palsy (CP). Twenty-two ambulant children (15 females, 7 males, mean age 8 years 6 months, SD 2 years 9 months, aged 5 to 14 years) with diplegic (n = 14), hemiplegic (n = 7), and quadriplegic (n = 1) CP participated in this study. All were randomly assigned to either the stimulation or control group. The stimulation group (n = 11) received electrical stimulation of the gluteus maximus of the most affected legs for 1 hour a day, 6 days a week for a period of 8 weeks. Electrodes were applied proximally and distally over the gluteus maximus, with the active electrode initially positioned over the motor points. The control group (n = 11) did not receive any extra treatment. Measurements of hip extensor strength, gait analysis, passive limits of hip rotation, and section E of the Gross Motor Function Measure were made before and after treatment for both groups. Subjectively, 7 of the 11 parents thought that the treatment made a difference to their child. However, no statistically or clinically significant improvement was found in the stimulation group when compared with the control group.