A Jehovah's Witness who requires thoracic and cardiovascular surgery represents a challenge to both the surgeon and the patient because of the patient's refusal to accept blood transfusion. We reported 15 cases of Jehovah's Witness patients from 43 to 80 years of age who underwent cardiac operations or thoracic vascular operations. There was 1 emergency operation case and 2 re-do operation cases. Erythropoietin and serum albumin injections were allowed to be used in some cases. The mean pre-operative haemoglobin level in these patients was 12.3 g/dl. The mean postoperative lowest haemoglobin level was 9.2 g/dl. The mean haemoglobin level at the point of leaving hospital was 11.4 g/dl. There were no postoperative complications and no operative deaths. We successfully performed the thoracic and cardiovascular operations on Jehovah's Witnesses, including emergency cases, safely without blood transfusion. The most important thing is a careful and safe operative technique which reduces perioperative bleeding as much as possible.