The UK Cystic Fibrosis Survey holds data on all people resident in the UK who were diagnosed as having cystic fibrosis and born either since 1968 or before 1968 and alive in 1977. Thus, incidence may be reported from 1968 and prevalence from 1977. The previous estimates are updated to the end of 1995 from data held in the database on 23 August 1996. The incidence is now calculated as one in 2415 live births. The 1992 mid-year population was 6500 people with 65% aged under 16 years. Births outnumber deaths by 160 per year, which suggests a population of 7750 by the year 2000, with all the increase being in the adult age range. The survival of successive cohorts continues to be better than earlier cohorts, the linear descent of the curves is still evident. The infant mortality rate for cystic fibrosis is now under 20 per thousand per year and early childhood mortality is under five per thousand per year. The crude mortality rate for 1995 was 21 per thousand per year, but the standardised mortality ratio was about 3300.