KCNQ genes encode for voltage-gated potassium channels (Kv7) that are crucial determinants of neuronal resting membrane potential and cardiac action potential. They are rather enigmatic channels because they undergo heteromeric assembly and associate with auxillary proteins encoded by the KCNE gene family resulting in very different biophysical and pharmacological attributes. It is generally accepted dogma that KCNQ1-encoded channels have a prominent role in defining cardiac action potentials and in epithelia, whereas KCNQ2-5 are predominantly expressed in neurones with KCNQ4 restricted to the cochlear and auditory nerves. Recently, we have shown that KCNQ1, 4 and 5 are expressed in various rodent and human arteries and that the expression products have a crucial physiological role both in the control of vascular tone by themselves and as a functional endpoint for ?-adrenoceptor-mediated signals. Other work has implicated Kv7 channels in the vasorelaxant response to other endogenous molecules. Recent findings have identified that Kv7 activity is compromise din hypertensive animal models and the combined data provides a framework for impaired vasorelaxation in hypertensive arteries.