One of the best events in the life of couples is having a baby, and it represents the chief goal behind marriage for many of them. However more than 15% of couples failed to achieve this and said to have subfertility. With the progressive alteration of the human feeding behavior and lifestyles, favoring the development of obesity, there's been an alarming rise in subfertility, and obesity has been identified to be one of the major causes of subfertility. It was thought that obesity affects women's chances of bearing a baby, but recent researches now point in the direction of men as well in playing a part in subfertility. Fortunately, progresses in assisted reproductive technologies (ART) have assisted many subfertile couples to conceive and one type of ART is intrauterine insemination (IUI). Despite the great advances in these technologies, the success rates are still low, and investigation of the factors that impact IUI may help to improve it. Therefore, the primary aim of this study was to investigate whether increased male body mass index (BMI) affects the outcome of IUI.