We report survival data for Danish centre-treated cystic fibrosis (CF) patients, covering the period 1974-1993 using cross-sectional cumulative survival probability based on annual age-specific mortality rates. No significant differences were noted in the survival probability when patients were grouped according to sex or absence/presence of meconium ileus. The annual mortality rate for 1989-1993 was 0-1.2%. Using the age-specific mortality rate for 1989-1993, we were unable to calculate the median survival probability because the curve did not fall below 50% (age up to 45 years). It was, however, possible to show that the survival probability for a CF child born after 1989 to reach his or hers 45th birthday was 80.4% (95% confidence interval 76.5-84.6%). The probability of surviving 40 years after the diagnosis of CF is made was 83.3% (95% confidence interval 80.1%-86.6%). This is considerably higher than any other published survival probability. An aggressive anti-Pseudomonas aeruginosa treatment regimen seemed important in achieving the observed improved survival.