BACKGROUND The literature on the best treatment of osteochondritis dissecans of the talus (OCDT) in children is scarce because of rarity of the condition. In addition, patients with this condition typically become asymptomatic long before radiographic healing is complete that might give a false perception of clinical success. We determined the healing rate after 6 months of nonoperative treatment of OCDT in skeletally immature patients. METHODS Retrospective review. METHODS After institutional review board approval, a retrospective review of clinical and radiographic records of children treated nonoperatively for OCDT between 1994 and 2005 at our hospital was performed. Subjects who had open growth plate at the time of presentation and no multiple trauma-associated OCDT lesions were included. Thirty-two subjects had open growth plates and completed at least 6 months of follow-up; 31 patients were initially treated nonoperatively, whereas one had stage 4 lesion and was treated surgically from the start. RESULTS After 6 months of nonoperative treatment of juvenile OCDT in 31 skeletally immature subjects with a mean age of 11.9 years, 77% continued to have persistent lesions on radiograph, 16% had complete clinical and radiographic healing, and 6% had severe pain after cast removal that required surgery. In those with radiographic persistent lesions and after an extra 6 months of nonoperative treatment, 42% had to undergo surgery for unhealed lesions and pain, whereas 46% had no symptoms despite persistent lesions on radiographs. CONCLUSIONS In skeletally immature patients, few juvenile OCDT lesions respond to 6 months of nonoperative treatment. This study demonstrated a higher rate of nonoperative failure than is generally reported in the literature. Prolonged conservative treatment, if opted after 6 months of nonoperative management, should include activity modification and out of sports until complete radiographic healing. Surgery should be adopted if pain persists and if the patient is not willing to modify activities. METHODS Therapeutic level IV.