Methods and apparatus for ablating blood vessels in treatment of uterine fibroids. A monopolar electrode provided on a needle probe is positioned in an artery supplying blood to a uterine fibroid. Energy is supplied to the electrode to ablate the artery. In this way, the uterine fibroid and the surrounding tissues remain relatively undamaged, and the uterine fibroid, deprived of its blood source, is allowed to necrose and eventually shrink.