Abstract: Large conductance Ca2+-activated K+ (BKCa) channels are abundantly expressed in vascular smooth muscle cells (VSMCs). Activation of BKCa channels leads to hyperpolarization of the plasma membrane, closure of Ca2+ channels, reduced intracellular Ca2+ levels and eventually vasodilation. Therefore, BKCa channels play an important role in determining membrane potential and regulation of vascular tone. The elevated vascular tone observed in human hypertension and in several experimental models of hypertension points to abnormalities of the expression and function of Ca2+ and/or K+ channels in VSMCs. VSMCs are more depolarized as a consequence of the ‘ion channel remodeling’ that occurs during chronic hypertension. In this review, we will mainly focus on BKCa channels in VSMCs that are reported to be altered in hypertension.