Femoral osteotomy is performed for osteonecrosis of the femoral head to prevent the progression of collapse and promote the repair process by transposing the necrotic lesion to the nonweight-bearing portion. The purpose of this review article was to summarize the current knowledge on two types of femoral osteotomy: transtrochanteric anterior or posterior rotational osteotomy and transtrochanteric curved varus osteotomy, both of which are currently performed for osteonecrosis, mainly in Japan and Korea. Osteotomy can be expected to cure osteonecrosis, and no matter how much the durability of artificial joints improves, there will always be young patients for whom the procedure is indicated. We should continue to verify the results of this surgery and refine the techniques involved.