Benefits of treatment for obstructive sleep apnea (OSA) in children with cerebral palsy could differ from those in otherwise healthy children. We examined the effects of OSA treatment by comparing a group of children with cerebral palsy treated with adenotonsillectomy or continuous positive airway pressure (CPAP) by nasal mask with controls who had not received treatment. Parents completed a structured questionnaire assessing change in their child's quality of life (QOL) and OSA symptoms after treatment, or between 6 months ago and the present time for controls. Fifty-one children were eligible, of whom 19 (37%) completed questionnaires: treatment group, n = 10 (adenotonsillectomy 7, CPAP 3); and controls, n = 9. The treatment group showed an improvement in OSA symptoms compared to controls, especially sleep disturbance (p = 0.005), daytime functioning (p = 0.03) and caregiver concern (p = 0.03). Parental QOL score improved by a mean of 18% in the treatment group (p = 0.06 for a difference from controls). Treatment of OSA in children with cerebral palsy leads to significant benefit in some aspects of health and QOL.