The mammalian transient receptor potential (TRP) superfamily of non-selective cation channels can be divided into six major families. Among them, the "classical" or "canonical" TRPC family is most closely related to Drosophila TRP, the founding member of the superfamily. All seven channels of this family designated TRPC1-7 share the common property of receptor-operated activation through phospholipase C (PLC)-coupled receptors, but their regulation by store-dependent mechanisms involving the proteins STIM and ORAi is still discussed controversially. This review will focus on the proposed functions of TRPC proteins in cells of the vascular system (e.g. platelets, smooth muscle cells and endothelial cells) and will present data concerning their physiological functions analysed in isolated tissues with down-regulated channel activity and in gene-deficient mouse models.