Nonunion is a relatively rare, yet challenging problem after fracture of the femoral neck. Risk factors include verticality of the fracture line and presence of comminution of the posteromedial calcar, as well as quality of reduction. Treatment options consist of valgus intertrochanteric osteotomy versus arthroplasty. Treatment should be tailored to the individual patient, taking into account patient age and activity demands. This review outlines the principles and technical considerations for valgus osteotomy of the proximal femur in the setting of femoral neck nonunion.