Fungal infections are increasingly common in burn patients. We performed this study to determine the incidence and outcomes of fungal cultures in acutely burned patients. Members of the American Burn Association's Multicenter Trials Group were asked to review patients admitted during 2002-2003 who developed one or more cultures positive for fungal organisms. Data on demographics, site(s), species and number of cultures, and presence of risk factors for fungal infections were collected. Patients were categorized as untreated (including prophylactic topical antifungals therapy), nonsystemic treatment (nonprophylactic topical antifungal therapy, surgery, removal of foreign bodies), or systemic treatment (enteral or parenteral therapy). Fifteen institutions reviewed 6918 patients, of whom 435 (6.3%) had positive fungal cultures. These patients had mean age of 33.2 +/- 23.6 years, burn size of 34.8 +/- 22.7%TBSA, and 38% had inhalation injuries. Organisms included Candida species (371 patients; 85%), yeast non-Candida (93 patients, 21%), Aspergillus (60 patients, 14%), other mold (39 patients, 9.0%), and others (6 patients, 1.4%). Systemically treated patients were older, had larger burns, more inhalation injuries, more risk factors, a higher incidence of multiple positive cultures, and significantly increased mortality (21.2%), compared with nonsystemic (mortality 5.0%) or untreated patients (mortality 7.8%). In multivariate analysis, increasing age and burn size, number of culture sites, and cultures positive for Aspergillus or other mold correlated with mortality. Positive fungal cultures occur frequently in patients with large burns. The low mortality for untreated patients suggests that appropriate clinical judgment was used in most treatment decisions. Nonetheless, indications for treatment of fungal isolates in burn patients remain unclear, and should be developed.