Foot infections in diabetic patients are predominantly caused by gram-positive cocci, many of which are now antibiotic resistant. Because linezolid is active against these pathogens, we compared the efficacy and safety of intravenous and oral formulations with that of intravenous ampicillin-sulbactam and intravenous and oral amoxicillin-clavulanate given for 7-28 days in a randomized, open-label, multicenter study of all types of foot infection in diabetic patients (ratio of linezolid to comparator drug recipients, 2:1). Among 371 patients, the clinical cure rates associated with linezolid and the comparators were statistically equivalent overall (81% vs. 71%, respectively) but were significantly higher for linezolid-treated patients with infected foot ulcers (81% vs. 68%; P=.018) and for patients without osteomyelitis (87% vs. 72%; P=.003). Cure rates were comparable for inpatients and outpatients and for both oral and intravenous formulations. Drug-related adverse events were significantly more common in the linezolid group, but they were generally mild and reversible. Linezolid was at least as effective as aminopenicillin/beta-lactamase inhibitors for treating foot infections in diabetic patients.