Background: In this era of rapid advancements in assisted reproductive technologies, intrauterine insemination (IUI) is still widely offered to subfertile couples, as a cheaper and less invasive treatment option before proceeding to IVF. Objective: To determine the most suitable timing of hCG administration prior to intrauterine insemination for optimizing pregnancy outcome and success rate. Patients and methods: A randomized controlled study conducted in Obstetrics and Gynecology Department, Sohag University from 30 June 2018 to 30 June 2019 and included couples with unexplained infertility. A total of 110 patients were recruited in our study, 30 patients dropped out; where 20 patients were due to inadequate stimulation, bad endometrium or more than 3 follicles were present, 6 patients did not show up for folliculometry after being given treatment and 4 patients did not show up for the procedure after being given the hCG trigger. Results: This study showed an improved pregnancy rate when IUI was performed with a time interval of 24–36 h (13 case with positive pregnancy test). Conclusion: IUI after ovulation induction can be done any time between 24 and 48 h after hCG injection without significant differences in pregnancy rates.