BACKGROUND Any increase of cardiac biomarkers after coronary artery bypass grafting (CABG) indicates myocyte necrosis and is likely to be related to an impaired outcome. We investigated whether ischaemia-modified albumin (IMA), a biomarker of ischaemia, is also raised following CABG. METHODS We studied 50 stable consecutive patients undergoing elective isolated CABG on cardiopulmonary bypass, of whom 46 were men and four women, aged 64 +/- 9 years. Blood samples were obtained the day before the operation (pre-op) as well as immediately after the operation, 24 h postoperatively (post-op) and the fourth day post-op and assayed for creatine kinase, the MB isoenzyme of creatine kinase, cardiac troponin-I, albumin and IMA. RESULTS The typical rising and falling pattern of myocardial necrosis of all three cardiac enzymes was observed post-op (p <0.0001). IMA increased significantly following CABG at all three time points (113 +/- 43, 106.7 +/- 22.6 and 110.2 +/- 12.5 U ml(-1), respectively) compared with pre-op values (91.7 +/- 10.5 U ml(-1)), (p <0.0001); the sample immediately post-op was significantly higher compared with the following samples (immediately post-op vs 24 h, p = 0.008 and immediately post-op vs 4 days, p = 0.03, with no significant difference between the last two). IMA level changes during the study course were independent of the albumin changes. Haemoglobin decreased significantly post-op (p <0.0001 vs baseline) whereas serum creatinine did not differ during the study period. CONCLUSIONS IMA increases significantly following CABG but whether or not this carries a prognostic significance remains to be elucidated.