Patients with lower extremity peripheral artery disease (PAD) have a substantially increased risk for mortality as compared to healthy individuals. We aimed to evaluate the risk for all-cause mortality in PAD patients and in healthy controls during a 10-year follow-up period. Our hypothesis was that the mortality rates at 10 years would differ in diabetic and non-diabetic PAD patients. Our study group consisted of 331 consecutive patients with symptomatic PAD <75 years of age admitted to a tertiary care hospital, including 216 patients without diabetes and 115 with diabetes. Control subjects without atherosclerotic disease were matched to the patients in a 1:1 design by sex, age, and diabetes mellitus status. The outcome measure was all-cause mortality at 10 years. Mortality rates at 10 years were 29% in non-diabetic PAD patients versus 14% in age- and sex-matched non-diabetic controls (risk ratio (RR), 2.31; 95% confidence interval (CI), 1.54–3.47; p<0.001), and 58% in diabetic PAD patients versus 19% in age- and sex-matched diabetic controls (RR, 4.06; 95% CI, 2.67–6.18; p<0.001). Further, PAD patients with diabetes had a significantly increased risk for death within 10 years than did the non-diabetic PAD patients (RR, 2.51; 95% CI, 1.72–3.66; p<0.001). Diabetes was independently associated with outcome, and was the strongest predictor of death in multivariate Cox proportional hazards regression. We conclude that mortality rates at 10 years differ in PAD patients <75 years old with and without diabetes. Our findings suggest that future studies should apply distinct risk assessment strategies in the two PAD subgroups.