ABSTRACT
Osteoid osteoma is one of the rare benign bone tumors that seen more often at childhood and young adults. Delay in diagnosis is commonly seen and it leads to development of several complications. In this case, we reported a 10-year-old child with osteoid osteoma located in right proximal femoral diaphysis. He had a right femoral pain and thigh atrophy for one year and could not be diagnosed in this period, and we discussed the causes of delay in diagnosis, points to be considered in the diagnosis and treatment options.