In Tunisia, red blood cells (RBC) transfusion joins in a statutory frame but remains subject to failures because of the misunderstanding of legislation and regulations. Our purpose is to estimate the knowledge of the medical staff in the immunological safety of RBC transfusion before and after reading an auto-education CD-ROM. It is a study of evaluation of an intervention. Eighty physicians participated to the study. The evaluation was done using an anonymous questionnaire, containing seven questions with multiple choices (QMC) relating to several items. The rate of good answers (RGA) calculated by questions and by items took into account the impact of the CD-ROM on the improvement of the answers after reading. The global average mark is 2.9/7. The RGA to questions varies from 22.5 % to 76.3%. All participants answered correctly to more than 50% of all items. Two answered correctly to all items. Among the participants, 31.3% answered to all "important" items, concerning ABO blood groups compatibility and ultimate bedside test. The rate of participation to the final evaluation was 83%. The impact of the CD-ROM was important and statistically significant. In the final evaluation, the global mark raised from 2.9 to 5.8/7, 31.5% (vs 2%) answered correctly all the questions and 95.5% (vs 31.3%) answered correctly all "important" items. This study revealed a misunderstanding of the doctors in immunological safety of RBC transfusions. Auto-teaching by CD-ROM was efficient. An improvement of the knowledge by continuous training is necessary in our country.