Background and AimsDiabetic foot ulcers are the main complication of diabetes mellitus. There is limited information on the prevalence and factors of diabetic foot ulcers in Ethiopia, particularly to the study setting. The study aimed to assess the prevalence of diabetic foot ulcers and determinant factors among adult diabetic patients who attend the diabetic follow‐up at Adwa General Hospital, Ethiopia, 2019.MethodsAn institutional‐based cross‐sectional study was conducted. The data was collected using face to face interviews, direct observation, and a patient's records reviews. Data were cleaned, entered, and analyzed using SPSS version 23. Bivariate and multivariable logistic regression was used to identify factors associated with a diabetic foot ulcer. Finally, p < 0.05 in multivariable logistic regression was used to declare statistical significance.ResultsThe prevalence of diabetic foot ulcer was 13%. Being a rural residence (AOR = 7.180, 95% CI: 2.663–19.359), oral hypoglycemic medication (AOR = 2.521, 95% CI: 1.001–6.349), medication nonadherence (AOR = 4.480, 95% CI: 1.954–10.269), poor diabetic foot self‐care practice (AOR = 4.350, 95% CI: 1.378–13.731), lost to follow‐up (AOR = 4.838, 95% CI: 1.828–12.801), neuropathy (AOR = 4.938, 95% CI: 1.565–15.580), and alcohol drink (AOR = 4.178, 95% CI: 1.592–10.966) were the determinant factors.ConclusionThe prevalence of diabetic foot ulcer was high. Being a rural residence, oral hypoglycemic medication, medication nonadherence, poor diabetic foot self‐care practice, lost to follow‐up, neuropathy, and alcohol drinks were the determinants of diabetic foot ulcer. Health education on diabetic foot self‐care practice, alcohol drink, and the other determinants are important to prevent diabetic foot ulcer.