The authors undertook a study to evaluate the prevalence of ankle equinus and its potential relationship to high plantar pressure in a large, urban population with diabetes mellitus. The first 1,666 consecutive people with diabetes (50.3% male; mean [+/-SD] age, 69.1 +/- 11.1 years) presenting to a large, urban, managed-care outpatient clinic were enrolled in this longitudinal, 2-year outcomes study. Patients received a standardized medical and musculoskeletal assessment at the time of enrollment, including evaluation at an onsite gait laboratory. Equinus was defined as less than 0 degrees of dorsiflexion at the ankle. The overall prevalence of equinus in this population was 10.3%. Patients with equinus had significantly higher peak plantar pressures than those without the deformity and were at nearly three times greater risk for presenting with elevated plantar pressures. There were no significant differences in age, weight, or sex between the two groups. However, patients with equinus had a significantly longer duration of diabetes than those without equinus. Having a high index of suspicion for this deformity and subsequently addressing it through conservative or surgical means may help to reduce the risk of foot ulceration and amputation.