Ticlopidine is an antiplatelet agent that is used to reduce the occurrence of atherothrombotic arterial events. There have been major multicentre placebo-controlled trials evaluating its use in stroke, peripheral arterial disease and unstable angina. In rare cases, adverse haematological effects have been seen with ticlopidine. Ticlopidine has been associated with neutropenia in some of the major trials and in subsequent case reports it has been associated with aplastic anaemia, thrombocytopenia and thrombotic thrombocytopenic purpura, which have been fatal in some instances. Ticlopidine should be used only in patients with an established indication for its use. Patients should be educated about the potential adverse effects and complications associated with ticlopidine, including possible death. Finally, there should be careful attention to haematological monitoring to screen for and promptly detect any adverse effects.