Coxa vara is a deformity of the proximal femur in which the femoral neck-shaft angle is decreased. This can be the result of an acquired deformity, metabolic disorder, congenital syndrome, or idiopathic (developmental). In this paper we primarily discuss developmental coxa vara but parsing out the etiology of the coxa vara has important implications in treatment. Coxa vara from a metabolic cause, for example, must be treated medically before a surgical intervention. In this paper, we discuss the unique radiographic characteristics of developmental coxa vara, as well as, radiographic measurements that can be used to determine severity. When surgical intervention is required, a proximal femoral valgus osteotomy is indicated. While proximal femoral valgus is a common deformity seen by pediatric orthopaedic surgeons, coxa vara is uncommon Most pediatric orthopaedic surgeons are facile with the varus proximal femur osteotomy but may not be as familiar with a valgus producing osteotomy. There are several planning and technical differences between the two procedures. With careful preoperative planning, the surgeon can avoid recurrence of the deformity. In this paper, we describe our pre-operative planning algorithm, our surgical technique, and post-operative protocol.