Males with diabetes mellitus have been reported to have low serum testosterone levels relative to the general population. This study aimed to explore the impact of glycemic control, duration of diabetes (in years), comorbidities, and diabetes complications on serum testosterone levels in different age groups. Using a cross-sectional study design, data were collected from the files and lab results of 350 diabetic male patients at King Salman Armed Forces Hospital in Saudi Arabia. We obtained data about their age, serum testosterone levels, hemoglobin A1c (HbA1c), the duration of diabetes (in years), coexisting comorbidities (if present), and diabetes mellitus complications. Patients in this study were found to have significantly lower serum testosterone levels than the average population and by looking at each factor independently, we come to find that glycemic control was the only factor found to substantially impact testosterone levels in diabetic males. Moreover, poor glycemic control (HbA1c ≥7%) Alone was associated with lower serum testosterone levels regardless of the presence of other factors such as the duration of diabetes (in years), age, comorbidities, and micro/macrovascular complications. In conclusion, the presence of the other factors was not found to have significant effect on serum testosterone levels unless accompanied with poor glycemic control. Along with this finding, further studies are required to better understand the exact mechanism of glycemic control’s impact on testosterone levels.