This is a prospective observational study of a consecutive series of 34 children with spastic cerebral palsy treated at a single center. 10 had spastic quadriplegia and 24 had spastic diplegia. All were followed for at least one year. After selective dorsal rhizotomy (SDR), all children received one month of physical therapy at the center and were prescribed a program of physical therapy in their community. The children were assessed before and one year after SDR and physical therapy, using the Ashworth Scale, deep tendon reflex response, range of motion and the Gross Motor Function Measure. The results show that there is often a decrease in lower-extremity spasticity and functional improvement after SDR with physical therapy, but that there is considerable variability in outcome. Randomized prospective clinical trials with masked objective outcome measures are needed to determine the efficacy of SDR.