The purpose of this retrospective study was to determine whether or not there was a significant relationship between women’s age as a cause of sterility and pregnancy after IUI. Furthermore, we evaluated the effect of stimulation of antiestrogens and time of hCG administration on the success of IUI in relation to the age of women. During the period between 2008 and 2012, we performed a total number of 793 IUI. Patients were prepared for IUI in the natural cycle and stimulation with antiestrogens (clomiphene citrate-CC). Ovulation was induced by hCG (Ovitrelle) 40 hours before IUI or immediately after the procedure. Sperm was processed through density gradients. The average success rate of IUI was 10.2% of pregnant women per cycle. Significantly the highest number of pregnant women 16.3% was women with a diagnosis of anovulation. Significantly the lowest success rate of IUI was at the immunological cause of infertility and endometriosis. There was no evidence of age dependence for women on the success of IUI. Stimulation of CC did not significantly increase the chance of becoming pregnant. There was also no statistically significant difference in hCG before and after IUI pregnancy success. The most important group of women for whom IUI is a suitable form of assisted reproduction consists of patients of 35 years old with anovulation cause of sterility. Those patients with an immunological cause of infertility and endometriosis have significantly lower chances of conceiving after IUI and it is preferable for them to choose other techniques of assisted reproduction and embryo transfer.