Background. Few data exist concerning the assessment of medical students' knowledge of universal precautions. The purpose of this study was to assess what students know-immediately before they graduate - about universal-precautions procedures. Method. The 151 fourth-year students of the class of 1992 at the University of Washington School of Medicine were given a questionnaire one week before graduation. They were asked to indicate the protective equipment required to safely complete ten common clinical procedures. For each procedure, the proportion of students who correctly indicated the protective equipment was calculated. Results. The questionnaires were completed by 137 (91%) of the students. The mean percentage of correct answers by the responding students was 67%. For five of the ten procedures, from 104 to 123 (76-90%) of the students reported the proper levels of protection. For the remaining five procedures, from 58 to 75 (42-55%) of the students knew the proper levels of protection. Conclusion. The results of the survey are worrisome, because many students-immediately before they graduated - lacked adequate knowledge of universal precautions regarding the ten common clinical procedures. More emphasis on universal precautions during undergraduate medical education is needed.