Changes in lung cancer incidence in south-east Netherlands between 1960 and 1991 were analysed, using data from the Eindhoven Cancer Registry, and related to previous changes in smoking habits. Male lung cancer incidence rates increased markedly from birth cohorts 1890-1899 to 1910-1919, followed by a decline. The peak incidences for both squamous cell carcinoma and small cell carcinoma were reached in 1978, while for adenocarcinoma it was 1985. A rising trend in female lung cancer incidence up to 1988 was found for each successive birth cohort and for every histological type. These changes in lung cancer incidence rates are most likely related to the pattern of past smoking habits: the percentage of male adult smokers in the southern part of the Netherlands decreased from 95% in 1960 to 40% in 1981 and the percentage of female adult smokers increased from 27% in 1960 to 40% in 1967, slightly decreasing only after 1979. In view of the trends in smoking behaviour, the incidence rates for male lung cancer will decline further, whereas female lung cancer incidence may decrease after the year 2000.