Aim: To determine the effect of body mass index (BMI) on semen parameters in men with subfertility. Methodology: The present study was a cross-sectional study conducted from 1^st January 2021 to 30^th June 2021. All subfertile couples having male factor subfertility attending the subfertility clinic were asked to participate. The weight and height of all men were recorded, and they were asked to submit a semen sample to the reference lab. The results of the semen analysis conducted as part of an initial assessment were compared with the following World Health Organization (WHO) reference values. Results: We included 347 males in the analysis. The mean age of the participant was 31.06 ± 4.89 years, and the mean duration of subfertility was 3.58 ± 1.62 years. Of these, 60.5% had primary subfertility. There were 44.4% of men with normal BMI and 9.8% were underweight. In our study population, 41.5% of men were overweight, and 4.3% were obese. When stratified according to BMI, only motility was significantly affected by BMI (p = 0.044). Conclusion: A high BMI is associated with reduced motility of sperm in semen samples. Obese men are more likely to have abnormal total motile sperm count than men with normal BMI. Larger studies are needed to assess the relationship between semen quality and BMI.