Background: Despite all attempts to increase pregnancy rates, overall success rate of Intrauterine Insemination (IUI) is still not acceptable. Proof of ovulation is an important indicator to determine the time of IUI, but to date there is no test proving that the ovulation has definitely occurred. Objective: This study was aimed to compare the efficiency of ultrasound in measuring the size of follicles and urinary Luteinizing Hormone (uLH) kit in determining LH surge for IUI timing. Method: In this comparative, nonrandomized, not blinded clinical trial, 311 IUI cycles in 262 infertile couples who were candidate of IUI were assigned into two groups of ultrasound (n=100 cycles) and uLH kit (n=211 cycles) for IUI timing. Two weeks after doing the IUI, the ßHCG was checked, and chemical pregnancy was confirmed. Four weeks after positive chemical pregnancy test, the fetal heart activity was confirmed by pelvic ultrasonography to confirm clinical pregnancy. Results: Chemical pregnancy rate was lower in ultrasonography group but not significant in comparison to LH kit (14.3% and 18.4%, respectively (P= 0.11)). Clinical pregnancy rate in the groups of ultrasonography and LH kit was respectively 10.3% and 10.3% which did not differ significantly (P= 0.3). Conclusion: Considering that the use of uLH kit is a simple and low cost way and can be done at home by the patients, so the patients can have an active participation in their treatment process.