Hairy cell leukaemia (HCL) offers one of the few examples of rapid progress in the development of effective treatments for chronic lymphoproliferative disorders. After the first description of HCL as a separate disease in 1958, splenectomy was the treatment of choice, but rarely resulted in remission of disease and had scarce benefit on survival. In 1984, IFN-alpha became the first agent able to significantly modify the prognosis of HCL by inducing high response rates and long-term remissions. More recently, purine analogues have significantly further increased the percentages of remissions, with a reduced risk of relapse and are now generally used as first-line treatment. Monoclonal antibodies targeting CD20, CD22 and CD25 antigens, have also shown responses for resistant or relapsing disease. This article will review the current treatment strategies for HCL.