Long-term treatment with bisphosphonates has been related to atypical femoral fractures. We report the clinical case of a woman who suffered a proximal diaphyseal oblique fracture of the left femur after uninterrupted 13-year treatment with alendronate. Shortly after surgery, a painful lytic image in the external cortex of her right femur diaphysis was detected. Some papers have suggested surgical treatment to repair femur fractures after long-term treatment with bisphosphonates. Otherwise, two studies have shown healing acceleration of bone fractures with teriparatide. A lytic lesion was treated with teriparatide obtaining progressive disappearance of symptoms as well as bone healing. This outcome may suggest a way of prevention of complete fractures in symptomatic patients with long-term treatment with bisphosphonates.