All patients with spastic cerebral palsy who underwent correction of valgus hindfoot by Grice extraarticular subtalar arthrodesis between 1971 and 1986 performed by two surgeons using an identical technique were reviewed. Twenty-nine patients (53 feet) were followed at an average of 8.9 years after operation. Traditional radiographic criteria for measurement of hindfoot alignment in skeletally mature individuals have poor reliability. Talar head uncovering is a useful and reproducible method for evaluation of hindfoot valgus in these patients. Five patients had progressive hindfoot or ankle deformity at latest follow-up. All five of these patients were spastic quadriplegics. There was no recurrence in the 17 patients who were less severely involved than the quadriplegic patients.