The aim of this study is examination effectivens of preventive vaccination against P. aeruginosa (PA) in patient hospitalized in the Department of Burn and Plastic Surgery District Rydygier Hospital, Cracow, Poland. The pothogen determine significant problem mainly patients with large burn wounds. The “Pseudovac vaccine was apllied in the study. The vaccination was discontinued between March 2006 and February 2007 due to temporary cessation of drug production. Clinical observations from the prophylaxis period and consequences of not administering the vaccine encouraged us to evaluate the influence of this prevention on the course of treatment. The study population consisted of 244 patients with burn wounds divided into two groups. The first group encompassed 125 individuals of both sex with burn skin areas covering on average 20,6% total body surface area [TBSA]. The second group recruited 119 patients of both sex with burn surfaces approximately 24,8% TBSA. The depth of burn injury in both groups was predominantly II/III and the mean burn skin area was 22,3% TBSA. We took into consideration the number of infections, bacterial culture samples taken from wounds and body fluids, general treatment time, treatment costs as well as the amount of septic shocks and deaths caused by P. aeruginosa. Statistical analysis of these data indicates, that 81,7% of infected wounds ocurred in the second group of patients. Only 18,3% infections were noted among patients receiving prophylaxis. We conclude that immunization against P. aeruginosa is safe and cost-effective among burn patients.