Osteochondromas are solitary masses that rarely cause pain or other symptoms. However, in cases of multiple hereditary exostoses (MHE) in which many osteochondromas are present, extremity deformity is more common. Surgical excision is considered in situations in which altered bone growth is affecting function or if the osteochondroma causes pain. Osteochondromas that affect the proximal part of the femur are common, reported to be involved in 30% to 90% of cases of MHE1-4, and can affect growth and morphology of both the femur and acetabulum. More specifically, coxa valga deformities have been reported in 25% of patients with MHE5, including femoral neck broadening, femoral anteversion, and valgus deformity together with acetabular dysplasia4,6. Proximal femoral varus-producing osteotomies have been described7. To the best of our knowledge, there have been no reported nerve injuries during a varus-correcting osteotomy of the proximal part of the femur in patients with MHE. However, one report of 164 proximal femoral osteotomies not associated with MHE described peroneal nerve palsies in two patients8. In this report, we examine the case of a young boy treated for proximal femoral valgus deformity in MHE with bilateral varus-producing osteotomy of the proximal part of the femur. We evaluate the surgical complication of bilateral peroneal nerve palsy and discuss the patient’s clinical course, including surgical treatment of the nerve palsies. The patient and his parents were informed that his case would be submitted for publication, and they provided consent. A nine-year-old boy with multiple previous surgical interventions related to MHE had been followed for painful bilateral hip dysplasia and valgus deformity of the proximal part of the femur. The patient had no additional symptoms regarding the lower extremities, and the physical examination demonstrated excellent strength and normal sensation. …