Purpose: This study was performed to determine the effects of ultrasound (US) guidance during intrauterine insemination (IUI) on pregnancy rate. Materials and Methods. This study is a prospective randomized controlled trial which was performed in Women’s Health Research and Education Hospital, Infertility Unit. The study enrolled 130 couples who were scheduled to undergo IUI. The couples were randomized according to a computer-generated list into two groups; 1) the ultrasound-guided IUI group included 64 couples (n = 64) treated for 99 cycles 2) blind IUI group included 66 couples (n = 66) treated for 104 cycles. All women underwent controlled ovarian stimulation before IUI. The study’s main measurements were pregnancy rate per cycle; pregnancy rate per woman. Results: The pregnancy rates were similar in both the ultrasound-guided (USG)(16.2%, 16/99) and non-ultrasound-guided (NUSG)(12.5%, 13/104) groups (p = 0.386). Conclusions: The present results suggest a routine ultrasound guidance during IUI is not essential as it does not increase pregnancy rates but it can be used in such cases to overwhelm some sort of difficulties.