Chronic myeloproliferative diseases (CMPD) are haematopoetic neoplasias with indolent course and preserved cellular function of the maturing malignant cells. In Philadelphia-positive chronic myeloid leukaemia the discovery of molecular disease mechanisms led to the successful introduction of targeted therapy with imatinib. Ph-negative CMPD are conventionally treated by cytoreduction and low dose ASS in order to minimise the risk of vascular complications. For all CMPD, lifelong surveillance and therapy are necessary.