Forty-four feet in 28 children previously treated by a one-stage posteromedial release operation (the Turco procedure) were reviewed clinically and radiologically to determine the cause of residual adduction of the forefoot. In 21 clinically adducted feet (48%) the main cause of residual deformity was metatarsus varus alone, or metatarsus varus in spite of talonavicular overcorrection; in five feet the cause was talonavicular subluxation. There was no residual adduction in 23 feet (52%) but only 12 had normal radiographic measurements. In the remaining feet, various forms of spurious correction of metatarsus varus and talonavicular subluxation or both were seen, resulting in normal-looking feet. Recession of the origin of abductor hallucis and release of the short plantar muscles and fascia at the time of posteromedial release is recommended. The forefoot adduction was satisfactorily corrected in 91% of the feet subsequently operated on using this modified procedure.