This chapter summarizes the current knowledge on prevalence and characteristics of cerebral microbleeds (CMBs) in normal individuals. The most solid knowledge on CMBs comes from the population-based studies, in particular those that have included higher age groups and have used a sensitive technique to detect CMBs. The four population-based studies with reported findings on CMBs in normal individuals are the Austrian Stroke Prevention Study, the Framingham Study, the Age Gene/Environment Susceptibility (AGES)-Reykjavik study (AGES-R) and the Rotterdam Scan Study. A pioneering study from Japan studied the prevalence of CMBs in 450 neurologically healthy Japanese adults with a mean age of 52.9 years. The overall incidence was 3.1% (14/450), and lesions detected were closely related to hypertension and heavy cigarette smoking. Patterns of risk factors and comorbidities are different between regions, and one can assume that such factors should also affect prevalence rates of CMBs.