We report a case of avascular necrosis of the epiphysis of the right first metatarsal in a 6-year-old boy. Radiographs showed sclerosis, collapse and a crescent sign in the epiphysis. The diagnosis was confirmed by magnetic resonance imaging and scintigraphy. Arch support was the therapy of choice. Six months after the onset of symptoms, a definite reossification was present. To our knowledge, this is the first radiological report of avascular necrosis of the epiphysis of the first metatarsal bone in the world literature, which prompted a review of the osteochondroses and their etiology.