Objectives: The aim of this study was to determine the effects of Cabergoline administration on uterine blood flow in women suffering from polycystic ovary syndrome (PCOS). Methods: This study is a randomized, controlled, triple-blind trial which is tested on 40 women who were randomly divided into two groups of 20 people and using a randomized block design during which the subjects were assessed and included. They were suffering from polycystic ovarian syndrome. Inclusion criteria were classically defined PCOS criteria including: oligomenorrhea or amenorrhea, clinical or Laboratory findings based on increase in blood level androgen (testosterone) and ultrasound confirmation of PCOS. Exclusion criteria were Pregnancy, lactation, Dopamine Agonist Therapy. After selection of intervention and placebo groups, primary control Doppler ultrasound was done for both groups. Then a weekly dose of Cabergoline 0.5 mg was administered to intervention group for duration of 12 weeks. Placebo group were administered placebo in the same fashion. At the end of 12 weeks, Doppler ultrasound was performed and the results were recorded in the check lists. Results: No significant difference was noticed in both groups with respect to their age, employment, level of education, type of infertility, duration of marriage, and results of RI and PI before intervention. Later PCOS patients under the treatment of Cabergoline showed a significant increase in uterine blood flow Pulsatility Index (PI) before 2.65±0.52 and after 1.98±0.52 and RI before 0.85 and after intervention 0.77), yet no significant difference were found in PCOS patient under the treatment of placebo. Conclusion: PCOS patients were shown to have more resistance in uterine blood flow than healthy people; however, Cabergoline administration proved to increase uterine blood perfusion and regulate menstruation cycle.