The cerebral endothelium represents an active interface between blood and central nervous system. The blood-brain barrier restricts the free passage of nutrients, hormones, drugs and cellular elements to the brain. Recent studies performed on freshly isolated cerebral microvessels and cultured endothelial cells of brain capillaries provided a better understanding of the properties and functions of cerebral endothelial cells. This review summarizes the main findings of the in vitro approach in the blood-brain barrier research, describes the common endothelial and unique cerebral features of the brain endothelium, and provides a short overview on how these blood-brain barrier characteristics can be induced in cerebral endothelial cells by the neighbouring cells.