Cerebral microbleeds (CMBs) have mainly generated interest in the context of common acquired cerebrovascular and neurodegenerative diseases, including ischemic stroke of various causes, spontaneous intracerebral hemorrhage (ICH) and Alzheimer's disease. Although the conditions considered in this chapter form a rather disparate grouping, they have been divided into the following categories: rare inherited cerebral microangiopathies (amyloid and non-amyloid related), cardiac conditions, hematological conditions, large vessel angiopathies (moyamoya syndrome), miscellaneous encephalopathies and renal disease. A number of other hereditary disorders affecting blood vessels of the brain and retina have been identified in recent years, including three autosomal dominant adult-onset conditions: cerebroretinal vasculopathy; hereditary endotheliopathy with retinopathy; and hereditary endotheliopathy with retinopathy, nephropathy and stroke (HERNS). Many hematological disorders are associated with vascular damage or coagulopathies, which can increase the risk of ischemic stroke, ICH or cerebral venous thrombosis.