Cerebral palsy is a common childhood condition, with spasticity being one of its most disabling complications. Botulinum Toxin has long been used as first line treatment. The authors performed a Cochrane review of all randomized controlled trials comparing Botulinum Toxin to placebo or an active comparator. Overall, 31 trials randomized 1508 patients. The overall quality of the evidence was low or very low. There was limited evidence that BoNT-A is more effective than placebo or non-placebo for improving gait, range of motion, satisfaction, and spasticity. The results for function were contradictory. The rate of adverse events is low and similar to placebo.