Traumatic avulsion fractures of the lesser trochanter are usually seen along with fractures of the proximal femur and with young adolescents involved in high-intensity sporting injuries. Atraumatic isolated lesser trochanter avulsion in adults are most commonly associated with malignancy. We describe a case of a female in her sixties who was previously fit and healthy with no systemic illness and no history of trauma presenting with groin pain. The X-ray demonstrated an isolated lesser trochanter avulsion fracture. Further imaging including MRI and a staging CT scan of the neck, chest, abdomen and pelvis revealed a pulmonary tumour. Biopsy later confirmed this as a non-small cell carcinoma of the lung. At the time of publication, she had been started on palliative chemotherapy (afatinib) with encouraging results.