Purpose: To investigate clinical features and treatment of os subfibulare Materials and Methods: This is a retrospective study on twenty-eight patients who have symtoms associated with os subfibulare. We reviewed charts and radiographs. Thirteen patients were treated surgically and fifteen patients were treated conservatively. We analysed clinical results in 25 patients who were followed for more than one year. Results: Duration from the onset of symtoms to treatment was more than six months in twelve of thirteen surgically treated cases, and in only two of fifteen conservative treated cases. Surgical procedures were internal fixation of the os subfibulare in two patients, and resection of os subfibulare and ligament reconstructions in eleven patients. Clinical results were excellent in six, good in three and poor in two of operatively treated patients. In conservatively treated patients, five excellent, five good, one fair and one poor clinical results were obtained. Conclusion: Os subfibulare is not necessarily a cause of instability and pain, but in cases with chronic pain and/or instability, surgical treatment would result in satisfactory result.