The authors retrospectively reviewed a series of 492 consecutive cerebral palsy patients undergoing computerized motion analysis. The prevalence of 14 specific gait abnormalities was evaluated and compared based on involvement (hemiplegia, diplegia, or quadriplegia), age, and history of previous surgery (lower extremity orthopaedic surgery or rhizotomy). Stiff knee in swing, equinus, and intoeing were all seen in more than 50% of the subjects in each of the hemiplegic, diplegic, and quadriplegic groups. Increased hip flexion and crouch were also present in more than 50% of the subjects in the diplegic and quadriplegic groups, and hip adduction occurred in more than 50% of the quadriplegic subjects. The likelihood of having stiff knee in swing, out-toeing, calcaneus deformity, and crouch increased with prior surgery. The likelihood of having rotational malalignment of the leg (internal hip rotation with out-toeing), calcaneus, out-toeing, varus and valgus foot deformities, and hip internal rotation increased with age. These findings provide important information for counseling ambulatory children with cerebral palsy and their families.