The purpose of this study was to compare the cumulative efficacy (three treatment sessions) of botulinum toxin A (BTX-A) alone, casting alone, and the combination of BTX-A and casting in the management of dynamic equinus in ambulatory children with spastic cerebral palsy (CP). Thirty-nine children with spastic CP (mean age 5y 10mo, range 3 to 9y) were enrolled in the study. A multicenter, randomized, double blind, placebo-controlled prospective study was used. Children were randomly assigned to one of three treatment groups: BTX-A only (B), placebo injection plus casting (C), or BTX-A plus casting (B+C). The dosage for the BTX-A injections was 4U/kg per extremity. Assessments were performed at baseline, 3,6,7.5, and 12 months with a total of three treatments administered after the evaluations at baseline, 3, and 6 months. Primary outcome measures were ankle kinematics, velocity, and stride length. Secondary outcome measures were ankle spasticity, strength, range of motion, and ankle kinetics. Group B made no significant change in any variable at any time. Groups C and B+C demonstrated significant improvements in ankle kinematics, spasticity, passive range of motion, and dorsiflexor strength. Results of this 1-year study indicate that BTX-A alone provided no improvement in the parameters measured in this study, while casting and BTX-A/casting were effective in the short- and long-term management of dynamic equinus in children with spastic CP.