The purpose of this study was to compare gait pattern and energy consumption in children with spastic diplegic cerebral palsy, when using anterior and posterior walkers, and to determine which walker should be recommended as a walking aid for these children. Ten spastic diplegic cerebral palsied children, of average age 9 years, were enrolled in this study. Before assessment, they had all received a practice period of 1-month to familiarize themselves with both types of walker. Gait characteristics were evaluated by computer-based kinematic gait analysis using Vicon 370 Motion Analysis, and energy expenditure was determined by KBI-C while they were using the walkers. The oxygen consumption rate was significantly lower whilst using the posterior walker, as was the oxygen cost. Walking velocity and cadence on gait analysis showed no significant difference between the walker types. However, step length, single support time and double support time were significantly different for the two walkers. Flexion angles of the trunk, hip and knee were lower using a posterior walker. Gait analysis data and oxygen consumption measurements indicated that the posterior walker has more advantages in terms of upright positioning and energy conservation than the anterior walker.