An Italian mother and identical male twins showed roentgenographic evidence of multiple osteochondrits with underdevelopment of the epiphyses, not associated with a definite hypothyroid state. No symptoms were associated with the osteochondritis except those of the hip joints. At the present writing, the mother has deformed femoral heads and necks which cause pain and limp. The one child whose epiphyseal changes left him with a deformed femoral head and neck also has moderate pain on active use, while the other child, whose left upper femoral capital epiphysis regenerated so that normal contour resulted, is symptom free.