Plantar puncture wounds to the foot are a common injury. A small number (1.8%) of these puncture wounds become infected and progress to osteomyelitis. The purpose of this article is to report the cases of six patients who developed osteomyelitis of the calcaneus after a puncture wound to the heel caused by a nail. The characteristics of the patients, the pathogenic organism, and the outcome were studied. Patients who were healthy and had no systemic illness (N = 4) had only one pathogenic organism cultured, whereas patients who had systemic illness (diabetes mellitus, N = 2) had more than one pathogenic organism cultured. The only amputation in this group occurred in a patient with diabetes mellitus. It was concluded that diabetic patients who develop calcaneal osteomyelitis from a nail puncture wound are more likely to have multiple pathogens cultured. Furthermore, if a diabetic neuropathy is also present, the nail puncture wound may be the initial injury leading to a chronic ulceration, increasing the risk of amputation.