Most physicians believe that diabetic individuals are predisposed to infections and that infection complicates the control of the diabetes. However, only bacteriuria can be documented to occur with increased frequency in diabetic compared with nondiabetic patients. Although most bacteriuric diabetic patients are asymptomatic, severe infections such as emphysematous pyelonephritis, papillary necrosis, perinephric abscess, and candida pyelonephritis may occur. Tuberculosis, once a proven threat to diabetic individuals, is a less serious problem now that effective screening and chemoprophylaxis programs have been initiated. Several unusual infections such as malignant external otitis, rhinocerebral mucormycosis, emphysematous pyelonephritis, and emphysematous cholecystitis occur also exclusively in diabetics. Foot infections are very important in diabetic patients; successful treatment requires accurate assessment of the extent and etiology of the infections and often involves surgery as well as broad antibiotic coverage. The important problem of infection in diabetic patients deserves careful evaluation. Questions such as do diabetic individuals have a higher incidence of infection, why are diabetic patients predisposed to infection, why is necrosis common in several of the infections, what is the course of asymptomatic bacteriuria, who do diabetic patients develop foot infections, and how should foot infections be prevented and treated should be topics of clinical investigation.