Cellular microvesicles are membrane nanometric vesicles, 0.1-1 µm in size, released into body fluids by activated cells or during apoptosis in a variety of pathological conditions. Microvesicles expose phosphatidylserine and tissue factor and have been proposed as pathogenic markers, key players of the haemostatic response. In recent years, tumour microvesicles have evolved as potential biomarkers. Indeed, tumour cells are able to constitutively release large amounts of microvesicles bearing tumour specific antigens. In hematologic malignancies the study of microvesicles is gaining increased interest and the generation of leukaemia/lymphoma cell-derived microvesicles may constitute a new tool for diagnosis and clinical/therapeutic follow-up.