The contractility of the human uterus is under the fine control of a variety of interacting bioactive agents. During labour, the excitability of the uterus is drastically transformed in comparison with the non-labour state and is manifest at the membrane level via the activity of uterine ion channels. This article reviews the contribution of potassium (K(+)) channels to human uterine excitability. Experimental Physiology (2001) 86.2, 255-264.