Background: Diabetes presents a multifaceted challenge to health systems in Nigeria and beyond. Physical activity is a cornerstone of diabetes management but is often underutilised. Despite the positive effects of physical activity on different dimensions of health to patients with diabetes, most fail to maintain long-term adherence to physical activity programmes. Objectives: This study aimed to determine the physical activity level and factors affecting exercise participation among patients with and without diabetes. Methods: This was a cross-sectional study involving 400 participants recruited by convenience sampling. International Physical Activity Questionnaire (IPAQ) and Exercise Benefit and Barrier Scale (EBBS) questionnaires were used to measure physical activity and perceived benefits and barriers to exercise, respectively. The data collected were analysed using descriptive statistics of percentages and frequency, mean and standard deviation, and independent t-test. The level of significance was set at p<0.05. Results: The majority of the patients with diabetes (71%) had low physical activity levels while 52% of the nondiabetic group were moderately active. There was a significant difference between physical activity levels of patients with diabetes and the nondiabetic group (p<0.05). Physical exertion was reported by both patients with and without diabetes as the greatest barrier to exercise participation. Conclusion: Patients with diabetes in Nigeria have a low level of physical activity and are also faced with certain barriers which limit their participation in exercise programmes. Exercise barrier identification and public awareness on the health benefits of exercise and physical activity in the prevention and management of diabetes should thus be encouraged.