The purpose of the current study was to investigate the results of occult fractures in the subtalar joint which were detected in delay and to find out a way of early detection. The occult osteochondral fractures of the subtalar joint are known to be associated with dislocation and to have a poor prognosis. We treated ten patients who had the occult fractures that were not associated with dislocation. Nine fractures involved posterior facet with a displaced osteochondral fracture. Seven patients lost motion in the subtalar joint completely, and arthrodesis were performed. Three subtalar joints retained some motion and were treated with physiotherapy, which improved the movement and pain. The early detection of fracture was important for the prognosis. We note the "early warning"signs of the patients who have massive swelling without definite bone injury, and who had a failure to regain the subtalar motion after immobilization. The subtalar joint should be imaged with CT or MRI. At first, aggressive physiotherapy should be considered. Arthrodesis should be considered as a final option.