A non-traumatic, incomplete insufficiency fracture commonly involves the lateral side of the femoral cortex; whereas a non-traumatic, incomplete stress fracture commonly involves the medial side of the femoral cortex. Here, we describe a case of a 66-year-old woman with a two-month history of bilateral thigh pain without trauma or medication usage who was diagnosed with bilateral subtrochanteric insufficiency fractures involving the medial side of the femoral cortex.