Transfusions with incompatible blood products including plasma are a well-known problem. The present study was performed to test the effects of Uniplas, universal plasma that can be transfused regardless of a patient's blood group, with respect to bleeding and hemostatic activity. The study comprised 84 adult patients scheduled for elective openheart surgery. A total of 55 patients received plasma transfusions, while 29 patients not requiring plasma served as controls. If plasma transfusion was indicated during operation or over the two following days, patients were randomised 2:1 to receive Uniplas or Octaplas of blood group AB. Relevant clinical observations were recorded and blood tests taken repeatedly. The transfused patient groups were comparable, and no significant differences were observed with respect to activated clotting time (ACT), activated partial thromboplastin time (APTT) or postoperative bleeding into chest drains. The median number of transfused units of Uniplas was 3, with a range of 1-23, while the median for Octaplas was 2 with a range of 1-11. These differences were not significant.Thus, Uniplas has a similar effect as Octaplas in the treatment of bleeding in patients undergoing openheart surgery. Uniplas can therefore substitute for Octaplas and eliminate the risk of ABO-incompatible transfusions.