To determine the rate of serious infection in closed and open calcaneal fractures that were treated with open reduction and internal fixation (ORIF) via an extensile lateral approach. Retrospective review. Level 1 trauma center. Two groups of patients with calcaneal fractures treated with ORIF via an extensile lateral approach by the senior author are included. The first group contained 341 closed fractures in patients injured during the period 1994-2000. The second group included 39 open calcaneal fractures in patients injured during the period 1989-2000. The age, sex, pre-existing medical conditions, compliance history, mechanism of injury, soft tissue status, presence of serious infection, and treatment of the infection were recorded for each patient. Data were gathered by review of patient records and by telephone interview when medical records were incomplete. The rate of serious infection in the closed and open samples was determined. A literature review yielded 15 reports that contained sufficient detail to calculate the rate of serious infection. Of patients, 1.8% with closed fractures and 7.7% with open fractures experienced serious infections that required intervention beyond oral antibiotics. All of these feet eventually healed their incisions and fractures. The calculations from data obtained from the literature review indicate rates of serious infection of 0-20% for closed and 19-31% for open calcaneal fractures. When done correctly in compliant patients, ORIF for calcaneal fractures via the extensile lateral approach (which allows for restoration of calcaneal anatomy after substantial disruption) does not expose the patient to undue risk of serious infection.