Background and aim of the study Referral patterns for aortic valve replacement have changed over time. The current study explores if the predictors for 30-day mortality also have changed between 1986 and 2006. \nMaterals and methods One-thousand files of patients who underwent aortic valve replacement were studied retrospectively. For four 5-year periods, twenty preoperative (non-cardiac, cardiac and valvular) and five perioperative factors were screened for their effect on 30-day mortality by an univariate chi-square analysis. To identify the independent predictors, the significant factors were entered in a multivariate logistic regression analysis. \nResults There were 530 males. The median age was 75(71-77) years and 610 patients also underwent CABG. Thirty-day mortality was 37/1000. Between 1986 and 1991 (mortality 6/80), only one independent predictor could be identified: age over 80 (p=0.043; Odds Ratio=11.8, 95% Confidence Interval=1.0-148.9). Between 1992 and 1996 (mortality 6/216) the only independent predictor was congestive heart failure (p=0.026; OR=6.7; 95%CI=1.3-36.4). Age over 80 showed a trend. Between 1997 and 2001 (mortality 12/345), the independent predictors were need for urgent surgery (p<0.001; OR=38.8; 95%CI=6.3-237.5), concomitant coronary artery bypass grafting (p=0.002; OR=2.4; 95%CI=2.4-48.1) and need for digitalis (p=0.015; OR=5.5; 95%CI=1.4-21.5). Between 2002 and 2006, (mortality 13/365), the independent predictors were chronic renal disease (p=0.009; OR=5.1; 95%CI=1.5-17.5), age over 80 (p=0.010; OR=5.4; 95%CI=1.5-19.4) and need for urgent surgery (p=0.025; OR=8.1; 95%CI=1.2-52.9). \nConclusions The 30-day mortality rate does not change noteworthy throughout the 20-year time span. Age over 80 remains a predictor throughout and need for urgent surgery has emerged as a major predictor from 1997 on. This predictor is liable for change, by earlier referral. This could improve the postoperative results.