The optimal approach to diagnosing and managing osteomyelitis of the foot in diabetes is unclear. Diagnosis is based on clinical signs, supplemented by a variety of imaging tests. Bone biopsy is the accepted criterion standard for diagnosis but is not used by many. Management traditionally involves surgical removal of infected bone, combined with antibiotic therapy. However, recent studies have shown that antibiotics alone may apparently eliminate bone infection in many cases. There is also evidence that early amputation of infected digits is frequently noncurative. Agreement on criteria for diagnosing osteomyelitis is required, and randomized trials are urgently needed, to determine the relative benefits of various surgical interventions and the optimal deployment of antibiotics. We review the microbiology of osteomyelitis of the foot in diabetes, the benefits and limitations of various diagnostic procedures, and the evidence for the effectiveness of both surgical and nonsurgical approaches to management.