Background: Cardiopulmonary health and its relationship with diabetes mellitus are very important but particularly underexplored in young undergraduate students of private Universities in Nigeria. This observational study investigated the effect of diabetic risk on cardiopulmonary health indices among healthy, consenting undergraduate students of a private university in Nigeria by a convenient sampling method. Cardiopulmonary health indices were assessed by anthropometry; cardiorespiratory fitness was determined by maximum oxygen uptake levels (VO 2 max), blood pressure and heart rates were measured using the Bruce treadmill protocol; oxygen saturation was determined by pulse oximetry, pulmonary function was assessed by spirometry; diabetes mellitus was risk determined by fasting blood glucose levels and the FINDRISC (Finish Diabetes Risk Score questionnaire which is a validated tool, for determining Diabetes risk; heart health awareness was determined by a modification of the healthy heart questionnaire (HHQ-GP-1) which is a standardized tool for heart health awareness and practices. Results: Results showed that the prevalence of diabetes risk was 38.8% in the sample population. The healthy heart questionnaire revealed that participants had poor diet (76%) or did little or no exercise (60%) and were also ignorant of what a normal blood pressure should be (72%). There was no significant difference between blood pressure (systolic and diastolic) and heart rates after physical exercise of those at diabetes risk and those not at risk (p > 0.05). Fasting blood glucose levels between those at diabetes risk and those not at risk was significantly different (p < 0.01). The cardiorespiratory fitness (VO 2 max) of those not at diabetic risk was not significantly higher than of those at risk (p > 0.385). Respiratory functions (vital capacity, forced vital capacity, and forced expiratory volume) of those not at diabetic risk were higher than those at risk, showing that diabetes may impair lung function. Though this was not statistically significant (p > 0.05), the result obtained cannot be disregarded. Conclusion: Universities and higher institutions of learning should incorporate regular health promotion and education programs that focus more on healthy lifestyles, physical exercise, and proper diet.