A case report of a 64-year old woman who presented with recurrent pelvic and hip pain secondary to an intra-osseous lipoma of the acetabulum (with intra-articular extension) is reported. An acetabular labral tear developed in association with this tumour. There was no history of trauma. Usually intra-osseous lipomas are asymptomatic. To my knowledge, this is the first case report in the literature of an intra-osseous lipoma of the acetabulum causing severe pelvic pain requiring laparotomy. Hip pathology should be considered in the differential diagnosis of recurrent pelvic pain. Intra-osseous lipomas tend to resolve spontaneously by fat necrosis altering their radiological appearance. Consistent with this case, a negative bone scintigraph does not exclude their presence.