Objective. To determine the prevalence and microbiological behavior of the infections in hospitalized patients in the burn unit of the University Hospital San Jose ( HUSJ ) at Popayan, Colombia, 2010-2011. Methods: A retrospective cross-sectional study was conducted in patients admitted to the burn unit of HUSJ between the years 2010–2011. Patients were characterized sociodemographic and clinically. The prevalence of nosocomial infections was estimated. Frequency and antibiotic resistance of microorganisms isolated was described. Data were analyzed using SPSS version 15. Results. 113 patients was enrolled, the average age was 17.7 years and male gender predominated (55.8%). Hot liquids (64.6%) were the principal cause, the average of body surface area burned was 11.3% and the average hospital stay was 19.8 days. 13.3% of the patients had some nosocomial infection. The most frequently diagnosed infections were sepsis (24%), urinary tract infection (20%) and pneumonia (20%). Staphylococcus aureus was the most frequent bacteria (41.7%) followed by Staphylococcus epidermidis, mostly meticilino-resistant. The mean length of hospital stay and burned surface area (BSA) in patients with diagnosis of infection was 36.6 days and 17.3% respectively. Conclusions. The prevalence of infection is similar to that reported in Colombia. The resistance of the isolates was high. The meticilinoresistance of Staphylococcus was associated with clindamicina resistance.