The availability of immunosuppressive agents, such as antilymphocyte globulin and cyclosporin, has had a major impact on the outcome of patients with aplastic anaemia. The majority of patients will show a response to immunosuppressive therapy. For those who fail to respond to an initial course, a second or further courses of immunosuppression can be given. Improvement in survival may also be due to the improved quality of supportive care available today for patients with aplastic anaemia. The additional use of haemopoietic growth factors such as granulocyte colony stimulating factor with immunosuppressive therapy requires further prospective randomised studies in order to evaluate whether they are of benefit for patients with aplastic anaemia. Because of the rarity of this condition, the use of multicentre prospective randomised studies is crucial for further evaluation of treatment modalities in aplastic anaemia.