Transvaginal sonography with color flow mapping has been used in order to study various parts of uterine circulation during fertile period and postmenopause. The Doppler wave forms were analysed by pulsatility index and maximum systolic velocity of uterine artery and its ascending branches. A significantly lower vascular resistance was established in distal parts of the uterine artery. This finding could very likely represent a consequence of the effect of ovarian hormones on the vessel wall during the cycle. That might be a physiological basis for capability of fertilisation and carrying the normal pregnancy and child birth. Furthermore, it has been shown that during postmenopause, when ovaries normally cease steroid hormone production, it is difficult to detect wave forms in common uterine artery. However, postmenopausal extraovarian production of estrogen increases uterine flow and may precede hyperplastic or malignant changes of the endometrium. In women with proven pelvic masses, abnormal waveforms were recorded showing decreased uterine impedance and increased flow velocities.