Medical faculty, blood center directors, and technologists were surveyed to assess current opinions of knowledge deficiencies in transfusion medicine among medical school graduates, housestaff, and practicing physicians. Over 90% of those responding believed additional training in transfusion medicine was needed. Nine categories of deficiencies were identified, with more than 40% of respondents' comments reflecting concern about the lack of knowledge of the use of blood and blood components. Clinical faculty and blood bankers differed in their assessments of the knowledge deficiencies in two of the nine categories. Information obtained in this survey is relevant to educational development in transfusion medicine.