Thalidomide acts on the microenvironment of myelodysplastic syndromes (MDS) by influencing cytokine networks, and growing evidence supports thalidomide’s usefulness in the management of haematological malignancies, such as MDS. The European Collaboration Group on Myelofibrosis with Myeloid Metaplasia reviewed patients who received at least four weeks’ thalidomide treatment, in doses ranging from 50 mg/day to 400 mg/day. The results showed that 30% of patients had increases in haemoglobin, and, of these, almost 40% became transfusion independent. Platelets were increased in a significant proportion of patients, and approximately 40% of patients had a reduction in their spleen size. Data on thalidomide and acute myeloblastic leukaemia (AML) are conflicting: a recently published study indicated that thalidomide does not have a role in the management of acute myeloblastic leukaemia (AML), while other studies suggest some patients may respond because of thalidomide’s ability to activate natural killer cells and cytotoxic T-lymphocytes. Partial responses to thalidomide treatment have been recorded in patients with lymphoma. In a phase II study to assess the activity of thalidomide in patients with Waldenström’s macroglobulinaemia, a partial response was seen in 25% of patients who received a starting dose of 200 mg, which was escalated in 200 mg increments every 14 days as tolerated to a maximum of 600 mg. Although further study is required, thalidomide shows promise in the treatment of a number of haematological malignancies, many of which currently have limited treatment options and poor prognosis.