This study examined the effect of massed practice in balance recovery of stability in six children (four males, two females; mean age 9 years 2 months, SD 2 years, range 7 years 5 months to 12 years 11 months) with cerebral palsy (CP). Four children were diagnosed with spastic diplegia (Gross Motor Function Classification System [GMFCS] level II) and two with spastic hemiplegia (GMFCS level I). A single-subject, multiple-baseline experimental design involving three pairs of children matched for diagnosis was used. A moveable forceplate system was used to test and train reactive balance control. Area per second (i.e. area covered by the center of pressure over a one second period) and time to stabilization from center of pressure measures were calculated following perturbations. The intervention phase consisted of massed practice on the moving platform (100 perturbations/day for 5 days). Analysis included hierarchical linear modeling and a repeated measures ANOVA. All children demonstrated a significant improvement in their ability to recover stability as demonstrated by reduced center of pressure area and time to stabilization following training. These improvements were still present 30 days following completion of training. Results suggest that postural control mechanisms in school-age children (7 to 13 years) with CP are modifiable.