Cerebral small vessel disease is difficult to directly visualize in vivo. Therefore, we rely on radiological phenotypes as surrogate markers of disease. The principal phenotypes of clinical interest are small, deep brain infarcts, cerebral white matter lesions, deep brain haemorrhages, and cerebral microbleeds. The causes or mechanisms underlying these phenotypes are understood in varying degrees of detail. This review aims to summarize recent knowledge regarding these phenotypes and place it in context with classical clinicopathological observations to provide mechanistic, clinical, and therapeutic insights into small vessel disease.