Objective To assess adherence to clinical practice guidelines for three interventions routinely used in critical care medicine. Design and setting Multicenter, 1-day cross-sectional observational study in 44 intensive care units in four countries. Patients A total of 419 patients hospitalized in participating ICUs on the day of the survey. Measurements and results Red blood cell transfusion (n = 29) was performed appropriately in 22 patients (76%), while among the 390 patients who received no transfusion 4 (1%) had a valid indication. Setting of tidal volume in acute respiratory distress syndrome, assessed in 45 patients, was deemed appropriate in 37 cases (82%). Prescription of stress ulcer prophylaxis (n = 128) was appropriate in only 24 patients (19%), while among the 268 patients who were not treated 28 (10%) had an indication. Conclusions The implementation of recommendations varies across different domains of care. While the adherence to current recommendations in routine practice is acceptable as regards tidal volume settings in acute respiratory distress syndrome, it is suboptimal for blood transfusion and prevention of upper gastrointestinal bleeding. Practice surveys are useful to inform strategies currently developed to assess practices of health-care professionals and develop strategies for more effective dissemination of medical knowledge.