Magnetic resonance imaging of patients with primary intracerebral haemorrhage has drawn attention to focal areas of signal loss, which were suggested to indicate hemosiderin deposition from earlier bleeds. Correlative histopathologic data have recently confirmed this assumption and support a strong association between the occurrence of microbleeds and various types of small vessel disease, such as hypertensive lipofibrohyalinosis and cerebral amyloid angiopathy. Therefore, microbleeds that are detectable by magnetic resonance imaging could be viewed as markers for vessel wall disorders with a higher tendency for intracerebral bleeding. This finding appears to be of diagnostic importance, but could also help to predict a patient's risk for spontaneous rebleeding or bleeding complications after anticoagulation.