There is some evidence of improved myocardial protection with warm continuous blood cardioplegia. Warm cardioplegia however implies warm (normothermic) cardiopulmonary bypass (CPB). We evaluated retrospectively the influence of bypass temperature on the intra- and postoperative course of 121 patients, operated on for valvular and/or coronary artery disease. Only elective procedures with continuous blood cardioplegia were included. The patients were divided in two groups: warm group (n = 78): normothermic CPB (venous temperature > 33 degrees C) cold group (n = 43): hypothermic CPB (< 33 degrees C). Results: normothermic CPB resulted in a significantly shorter CPB time (84 + 3 min vs. 98 +/- 6 min, p = 0.02, mean +/- 1 standard error of the mean). In addition there was a higher need for vasoconstrictive drugs during cold CPB (Noradrenalin: 19 +/- 3 micrograms vs. 90 +/- 32 micrograms, p = 0.003). There was no difference in enzyme levels on the first postoperative day (amylase, creatinkinase, creatinin), in postoperative complication rate (resuscitations, rethoracotomies, cerebrovascular incidents) and mortality (warm 3% vs. cold 2%) between the two groups. The postoperative time until extubation however was significantly shorter in the warm group (33 +/- 5 h vs. 60 +/- 11 h, p = 0.04). Conclusion: there is no evidence of increased morbidity due to normothermic CPB. The shorter time until extubation may be due to a improved postoperative lung function and/or a more stable hemodynamic postoperative course after normothermic CPB.