Normocytic anaemia is caused either by hypoproliferation of haemopoietic tissue or increased destruction of red cells. Osteopetrosis is a rare cause of anaemia. Infantile osteopetrosis (also called malignant osteopetrosis) is diagnosed early in life. But it is the adult osteopetrosis (also called benign osteopetrosis) which is diagnosed in late adolescence or adulthood that present as anaemia which is difficult to diagnose and treat. Approximately one half of patients are asymptomatic, and the diagnosis is made incidentally, often in late adolescence because radiologic abnormalities start appearing only in childhood. In other patients, the diagnosis is based on family history. Still other patients might present with osteomyelitis or fractures. We are presenting here an unusual case of osteopetrosis which was referred to us for the evaluation of anaemia.