OBJECTIVE: To evaluate French, Swiss, and Belgian intensive care physicians' knowledge about the pulmonary artery catheter. DESIGN: Survey study by questionnaire. SETTING: Eighty-six European university and nonuniversity intensive care units (ICUs). SUBJECTS: One hundred thirty-four ICUs identified from the directories of two European intensive care medicine societies were asked to participate. Five hundred thirty-five critical care physicians working in 86 ICUs participated. INTERVENTIONS: In any particular ICU, all physicians were to complete--simultaneously, anonymously and without prior notice--a multiple choice questionnaire consisting of 31 questions regarding all aspects of bedside pulmonary artery catheterization. This questionnaire was the same one already used and extensively validated in a similar study conducted several years earlier in the United States and Canada. MEASUREMENTS AND MAIN RESULTS: The percentage of correct answers per participant (score) was tabulated. Sixty-eight percent of respondents still in training (n = 232) believed that their knowledge of the pulmonary artery catheter was less than adequate; 36% of those who had completed their postgraduate training (n = 294) also believed their knowledge to be inadequate. The mean score of all respondents was 72.2 +/- 14.4%, significantly lower (p <.0001) in case of uncompleted postgraduate training (67.3 +/- 14.7%, lower quartile 56.7%, median 70.0%, upper quartile 76.7%), as compared with completed postgraduate training (76.1 +/- 13.0%, lower quartile 70.0%, median 80.0%, upper quartile 86.7%). When using multivariate analysis, the location of the ICU in a university hospital, the belief of respondent that his/her knowledge of the pulmonary artery catheter was adequate, and the responsibility for supervising catheter insertion were the only independent predictors of good performance on the questionnaire (p < .001 for all three variables). It was impossible to identify any subcategory of physicians with a uniformly good knowledge of the pulmonary artery catheter. The proportion of incorrect answers to some basic items was disturbingly high. For instance, approximately 50% of the respondents, whether trained or in training, did not correctly identify pulmonary artery occlusion pressure from a clear chart recording. CONCLUSIONS: Knowledge of right-heart pulmonary artery catheterization is not uniformly good among ICU physicians. Accreditation policies and teaching practices concerning this technique need urgent revision.