It is well-known that diabetes is a risk for infection. According to our analysis of the cause of death in 221 diabetic patients over 10 years, infection and pneumonia accounted for 22% of all deaths. Diabetes may increase the risk of mycotic infections; however, few data are available on the prevalence of fungal infections in diabetic patients. The purpose of this paper was to analyze the clinical epidemiology of fungal infections in diabetic patients. Onychomycosis, oral candidiasis and vulvovaginal candidiasis are observed frequently in diabetic patients. Urinary tract candidiasis in diabetic patients frequently develops into systemic candidiasis and fungus ball formation in the kidney. An estimated 50-75% of cases of rhinocerebral mucomycosis occur in diabetic patients, and ketoacidosis is thought to be the most likely predisposing factor. Invasive otitis externa is almost exclusively found in diabetic patients, and generally caused by Pseudomonas. This has been described secondary to Aspergillus in diabetic patients. Regarding cryptococcosis in non-AIDS patients, approximately 10 to 20% of these patients have diabetes. Clinicians must be aware of mycotic infection in diabetic patients with infectious disease.