A rare case of the osteochondritis dissecans of the talus associated with giant cyst was reported.
A 17-year-old girl, who had severe pain and swelling because of sprain of recurrent planterflexion and inversion force of the ankle in playing handball games, was seen. The antero-posterior, lateral and mortise roentgenography, and lateral tomography were taken, which revealed osteochondritis disscans of the talus with giant cyst in the body, as Stage III according to the Berndt and Hartys classiffication, including mild osteoarthrotic changes.
The osteochondral fragment was excised with drilling after curettage by transmalleolar approach.
The aetiology, diagnosis and treatment of this case compared with some references was discussed.