Objectives: To assess nosocomial infections in a burn care centre, to identity patients' infection risk factors at the time of admission and factors of monthly variations of infection incidence. Study design: Prospective survey, from October 1992 to September 1993. Patients and method: The study included 140 patients staying for more than two days in a 22-bed burn unit. Nosocomial infection criteria were derived from the 1988 CDC critera. Incidence rates of infection were calculated. Infected and noninfected patients were compared. Each monthly infection incidence was compared with six unit activity indicators. Results: Fifty-six patients developed 132 infections. The overall incidence was 94%. Incidence density was 25 infections per 1,000 days of care. The distribution of infected sites was: skin (30%), intravascular catheters (25%), blood (22%), urinary tract (18%), respiratory tract (5%). The most frequent pathogens were Pseudomonas sp (49%), Staphylococcus sp (18%), Escherichia coli (18%), and Streptococcus faecalis (10%). They were characterized by a good antibiotic sensitivity. Each common burn severity index was predictive of nosocomial infections. Facial, perineal and respiratory lesions were also linked to infection. There was a positive correlation between the peak of nosocomial infections in the unit during a month and the peak of activity during the foregoing one. Conclusion: Incidence rates of infection were high, as 40% of the population was concerned. Choosing reliable infection criteria was the most difficult problem to solve.