objective. to compare morbidity and mortality of cardiac surgery patients according to age below or above 75 years. design. descriptive retrospective study. patients. a total of 2,470 consecutive patients admitted to our intensive medicine unit between november 2000 and december 2005 who were in the immediate postoperative period after cardiac surgery. of these patients, 1,983 were younger than 75 years and 497 were older than 75 years. main variables of interest. cardiovascular risk factors (diabetes mellitus, arterial hypertension and dyslipidemia), euroscore (european system for cardiac operative risk evaluation) and logistic euroscore, length of stay, mortality, complications during intensive care unit (icu) stay. results. in-hospital mortality of patients older than 74 years was significantly higher (9.2% versus 4.2%, p < 0.05). the morbidity of patients over 74 years of age was also significantly higher (euroscore 8.2 ± 2.7 versus 4.9 ± 3.3, p < 0.001). both icu stay and hospital stay were significantly higher in those over 74 years of age. conclusions. in our series both morbidity and mortality were higher in those older than 74 years of age group, which entails worse results in cardiac surgery of these patients. keywords: cardiac surgery, sternotomy, cardiopulmonary bypass, mortality, postoperative care, elderly.