Objective: OHSS appears to be induced by the ovarian release vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR2), causing increase vascular permeability (VP). Dopamine agonist (DA) inhibit VEGF / VEGFR2 and thereby decrease VP. The aim of this study was to determine the efficacy of non#ergot derived Dopamine agonist Quinagolide (Norprolac: Ferring Pharmaceuticals) in preventing OHSS in high risk women undergoing ICSI, and how would it affect the outcome? Design: Randomized control prospective study was performed in the period from June 2007 to June 2010 Materials and Methods: A total of 272 women undergoing ICSI and at high risk of developing OHSS, were recruited for this study: # E2 level on day of HCG ≥ 4000 pg/ml # ≥ 20 follicles ≥ 10 mm # Patients were similar as regards age, cause of infertility (male factor), BMI, long protocol, and luteal phase support. On day of HCG the patients were randomly divided into 2 groups: Group 1 (study group: 136 patients): were given Quinagolide (Norprolac) 150 mg daily from the day of HCG administration for 15 days. Group 2 (Control group: 136 patients): were not given Quinagolide. # OHSS symptoms were assessed according to Golan's classification system 4, 8 and 12 days after HCG administration. # Ascites was determined by transvaginal ultrasound. Results: The incidence of OHSS in group 1 was 4.41%, while it was 19.12% in group 2 (P <0.0001). The incidence of patients with Ultrasound evidence of ascites within the initial 8 days after HCG administration was significantly reduced from 15.44% (21/136) in group2 to 2.21% (3/136) in Quinagolide group (P <0.0001). There was no significant statistical deference between two groups in the number of oocytes, fertilization rate, implantation rate, clinical pregnancy rate, and in frequency of moderate and sever late OHSS. Conclusions: The present study indicates that Quinagolide (Norprolac) is effectively reduced the development of OHSS in high risk ICSI patients without affecting the clinical pregnancy rate. Keywords : Quinagolide, OHSS, ICSI.