The National Mortality Database of Statistics Canada was used to study chronic obstructive pulmonary disease (COPD) mortality trends between 1950 and 1984 by age, sex, birth cohort, and province. Provincial hospital statistics were combined for the period 1971 to 1984 to determine age-specific hospital separation rates for COPD. Utilization of physician services for COPD was determined for one province using physicians' claims for payment. Results of these analyses indicate that mortality from COPD has leveled off for men and is increasing for women; the trend is different for combined chronic bronchitis-emphysema and for asthma. Mortality from COPD varies by age, sex, birth cohort, and province. Mortality from COPD stopped increasing with the 1910 to 1914 birth cohort in men and the 1920 to 1924 in women. Male and female birth cohorts born after 1920 to 1924 have decreased mortality. It is speculated that the age-standardized mortality will decrease in the near future. Surveys of smoking habits over time support the hypothesis that a proportion of sex, birth cohort, regional, and socio-economic variation of COPD mortality is due to smoking. Hospital morbidity is higher for men than for women particularly for those more than 65 yr of age. Between 1971 and 1983, mortality/morbidity ratios were relatively stable. Asthma mortality and morbidity are increasing; changing concepts about the disease may be one reason for this observation.