BACKGROUND: Immune and infectious complications are associated with burn injury. Opiate analgesics also can induce similar complications, however, their impact on postburn infectious complications is unknown. METHODS: A retrospective survey of records from 1997 to 2002 from an academic burn center was conducted. Information on all opiate analgesic use was obtained and expressed as opiate equivalents (OEs). Total OEs were summed for each patient and then compared between cases and controls. RESULTS: Patients who developed infections were more likely to be in the high OE group. This association was modified by burn severity. Patients with small burns and infection were more likely to be in the high OE group, whereas patients with moderate to large burns and infections were not associated significantly with opiate use. CONCLUSIONS: The results of this preliminary study suggest that opiate analgesics can contribute to the development of postburn infectious complications when the burn injury is of a less severe nature.