Nail-Patella Syndrome (Hereditary osteo-onychodysplasia) is a rare disease that affects tissues of both ectodermal and mesodermal origin. We described both radiolgical and clinical features of 7 patients with this syndrome. In addition to plain roentgenograms, we studied the appearance of iliac horns on computerized tomography (CT) and magnetic resonance imaging (MRI) in two patients, and three-dimensional CT reconstruction of iliac horns was carried out in one patient. Variable combinations of anomalies, such as nail dystrophy, wrist and knee dysplasia, bilateral iliac horns and foot abnormalities were observed in all patients. Iliac horns appeared to consist of both cortical bone and medulla.