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Background and purpose: The clinical outcome of intrauterine insemination (IUI) treatment cycles employing a gonadotrophin-releasing hormone agonist [Superfact)] or human chorionic gonadotrophin (HCG) for ovulation induction was compared. Materials and methods: A group of 100 patients presenting with amenorrhoea, oligomenorrhoea or unexplained infertility were all treated with clomiphene 100 mg for 5 days and human menopausal gonadotrophins (HMG) from day 3 of the cycle, on an individualized schedule. They were then randomly divided into two groups to receive either a single s.c. injection of 0.5 mg superfact or a single i.m. injection of 10,000 IU HCG after follicular maturation. IUI was performed approximately 34 and 36 h following the injection. Results: patients received 51 treatment cycles with GnRHa, producing 11 conceptions (22.9%) and two abortions (3.9%), mature ovarian follicles was 3.4±0.08. patients underwent 48 cycles treated with HCG, producing 18 conceptions (35.3%) and four abortions (8.3%) and mature ovarian follicles was 2.6±1.4. Conclusion: These results show that an s.c. injection of a relatively low dose of GnRHa can be as effective as HCG in induction ovulation but pregnancy rate is more by HCG in IUI treatment cycles