Patients undergoing major heart surgery (MHS) may be at increased risk for nosocomial infections. To assess the incidence and type of infections in MHS patients in European intensive care units (ICUs) and their quality of care, a questionnaire was sent to a selection of MHS ICUs in Europe. Seventeen hospitals from seven European countries participated. Overall, 53% of the ICUs received patients only for MHS and the other 47% were mixed. During the study period, 11 915 patients underwent MHS and 1181 (9.9%) developed one or more nosocomial infections. Ventilator-associated pneumonia (VAP) was the most common infection [median 3.8%; interquartile range (IQR) 1.8-4.9], followed by surgical wound infection (median 1.6%; IQR 0.8-2.3), catheter-related bloodstream infection (median 1.3%; IQR 0.8-2.1), mediastinitis (median 1.1%; IQR 0.4-1.6), urinary tract infection (median 0.6; IQR 0.4-1.4) and nosocomial endocarditis (median 0.2%; IQR 0.0-0.9). Median mortality was 4.7% (IQR 2.7-8.4) and median infection-related mortality was 1% (IQR 0.5-2.7). Regarding VAP, 18% of the ICUs did not routinely pursue a diagnosis. Microbiological information was quantitative in 35% of cases and exclusively qualitative in 65% of cases. An infectious disease specialist was regularly involved in VAP management in only 35% of the ICUs, and the therapeutic approach to VAP involved de-escalation in 59% of the ICUs. MHS ICUs in Europe still have a high rate of postoperative infections. Well-recognized routine practices for the diagnosis and treatment of VAP are not implemented regularly in many European institutions.