Polycythaemia vera, essential thrombocythemia and primary myelofibrosis are stem cell-derived clonal haemopathies classified in the group of myeloproliferative neoplasms. Their clinical course may be complicated by both arterial and venous (sometimes in unusual sites) thrombotic events. Although general risk factors contribute to the prevalence of thrombotic events in this population, some other risk factors are specifically associated with the myeloproliferative neoplasms. The treatment options are aspirin, anticoagulation, cytoreduction and phlebotomies.