Thalassanemia is one of the most common monogenic disorders in Mediterranean countries, S.Asia and Africa. The main clinical manifestations include severe anemia which requires blood transfusion, liver and spleen swelling bone diseases and skeletal complications, iron chelation and retardation of physical development. The annual incidence is 5-10 while in Greece 3000 persons suffer from thalassanemia. Αim:The aim of the present study was to investigate the knowledge of patients with thalassemia in major issues of their illness Methods-Material: The research was carried out (October 2007- May 2008) with the use of anonymous questionnaires addressed to thalassanemic patients (n=330) over 18 years of age who are being transfused in various hospitals in the Athens region. Results: 87% of the respondents declare that they suffer from β-thalassanemia, 54% are women and 50% are between 30-39 years of age, 88% of the respondents states that they are adequately informed regarding transfusion procedures, 81% reply the same regarding the nature of their disease and 76% also seem satisfied with information on the need to examine other members of the family. Percentages of satisfaction regarding the information provided are lower as far as the following issues are concerned: implications (67%), genetics of the disease (65%), side effects from medication (56%) and patients' rights (49%). As far as information on even more specific issues is concerned, the replies which consider this information as inadequate range from 32-40%. Conclusions: According to the findings information is considered to be sufficient as far as practical and procedural matters are concerned, but it lacks behind as far as patients' rights, information regarding new therapeutic methods and possibility of participation in research protocols are concerned. The respondents' wish for better and broader information on all investigated issues is more than obvious.