Background: In common with other coryneform species, Corynebacterium striatum colonizes the skin and mucous membranes of normal hosts, and is one of the more frequent corynebacteria isolated in the clinical laboratory. However, its clinical significance is often unclear as it can be difficult to distinguish between colonization and infection. Most reported cases of C. striatum infection are of endocarditis, pulmonary infection or are associated with prosthetic devices. We observed a number of cases of diabetic foot osteomyelitis in our hospital from which a heavy, pure growth of C. striatum was isolated from tissue or fluid samples.Methods: A review of the medical literature was carried out and did not suggest C. striatum was a recognised cause of diabetic foot infection. We identified all pure cultures of C. striatum grown in our laboratory from tissue and fluid samples. We carried out a review of the patients' medical notes recording details of past medical history, antimicrobial history including changes made upon isolation of C. striatum and the clinical outcomes following appropriate therapy.Results: Three tissue cultures and one fluid culture of C. striatum were identified. The three tissue cultures were from patients with diabetic foot osteomyelitis. The fluid sample came from a deep washout of a diabetic foot ulcer with underlying osteomyelitis, and the growth was both heavy and pure. The four patients were male, and had a mean age of 76 years, and all had a diagnosis of insulin dependent diabetes. They were all were treated successfully with targeted antimicrobial chemotherapy, and followed up for at least eight months posttreatment, with no evidence of disease recurrence.Conclusion: We report 4 cases of C. striatum osteomyelitis of the foot in patients with diabetes mellitus. We suggest that where C. striatum is isolated in pure culture from tissue samples from diabetic feet, it should not be discounted as contaminating flora but considered as a genuine cause of infection.