Foot infections are a common problem and an important cause of morbidity in patients with diabetes. We report a patient with type 2 diabetes, presenting with a chronic foot wound resistant to standard care, in whom the diagnosis of eumycetoma was made through histopathological examination of a bone biopsy specimen and confirmed by polymerase chain reaction (PCR). Diagnosis and treatment of eumycetoma are reviewed. Eumycetoma caused by Madurella mycetomatis is an uncommon cause of osteomyelitis in patients with diabetes in Europe, but should be considered in patients from endemic regions when (antibacterial) therapy fails.