An endometrial ablation method comprising passing sufficient RF current having a frequency of from 250 kHz to about 100 MHz through substantially the entire surface of the endometrium to heat the endometrium, in a single operation, to a temperature within the range of from 45.degree. C. to 90.degree. C. and preferably not above 70.degree. C. for a time sufficient to destroy the cells of the lining while maintaining the average temperature of the myometrium at a temperature below about 42.degree. C. The apparatus comprises a electroconductive expandable member such as a balloon for extending the organ and effecting electrical contact with the endometrial lining to be destroyed. The balloon is connected to a power source adapted to provide radiofrequency electric power having the desired characteristics to selectively heat the endometrial lining to the desired temperature. The balloon can be an electroconductive elastomer such as a mixture of a polymeric elastomer and electroconductive particles. Alternatively, it can be a non-extensible bladder having a shape and size, in its fully expanded form, which will extend the organ and effecting contact with the endometrial lining to be destroyed. One surface of the non-extensible bladder can be coated with electroconductive material. The coating can be applied to the inner surface of the non-extensible bladder if the bladder wall thickness is less than about 25 mm.