Recent trends in physician diagnosed chronic obstructive pulmonary disease (COPD) in the UK were estimated, with a particular focus on women. A retrospective cohort of British patients with COPD was constructed from the General Practice Research Database (GPRD), a large automated database of UK general practice data. Prevalence and all-cause mortality rates by sex, calendar year, and severity of COPD, based on treatment only, were estimated from January 1990 to December 1997. A total of 50 714 incident COPD patients were studied, 23 277 (45.9%) of whom were women. From 1990 to 1997 the annual prevalence rates of physician diagnosed COPD in women rose continuously from 0.80% (95% CI 0.75 to 0.83) to 1.36% (95% CI 1.34 to 1.39), (p for trend <0.01), rising to the rate observed in men in 1990. Increases in the prevalence of COPD were observed in women of all ages; in contrast, a plateau was observed in the prevalence of COPD in men from the mid 1990s. All-cause mortality rates were higher in men than in women (106.8 versus 82.2 per 1000 person-years), with a consistently increased relative risk in men of 1.3 even after controlling for the severity of COPD. Significantly increased mortality rates were also observed in adults aged less than 65 years. The mean age at death was 76.5 years; patients with severe COPD died an average of three years before those with mild disease (p<0.01) and four years before the age and sex matched reference population. While prevalence rates of COPD in the UK seem to have peaked in men, they are continuing to rise in women. This trend, together with the ageing of the population and the long term cumulative effect of pack-years of smoking in women, is likely to increase the present burden of COPD in the UK.