We analyzed the epidemiological characteristics of pneumonia in intensive care units of Polish hospitals. Among 11,587 patients, there were 191 cases of hospital-acquired pneumonia (HAP). The incidence of HAP was 5.6%, and that of ventilator-associated pneumonia (VAP) was 17.9%. The overall mortality rate was 12.6%, and the mortality rate for patients who received artificial ventilation was 15.0%. The predominant organisms causing HAP and VAP were Pseudomonas aeruginosa and Escherichia coli, and 21.1% of Staphylococcus aureus isolates were resistant to methicillin.