Several changes in smoking patterns over the past decades in Spain can be expected to result in a shift in lung-cancer mortality rates. We examined time trends in lung-cancer mortality from 1973–1997 using a log-linear Poisson age-period-cohort model. The standardized lung-cancer mortality rate for men almost doubled, from 31.4 per 100,000 in 1973 to 58.6 in 1997, with an average annual increase of 2.7%. Mortality increased for male generations born until 1952 as a consequence of the increasing cigarette smoking in successive birth cohorts. However, the slight downward trend observed for the 2 youngest generations suggests a more favorable outcome of the lung-cancer epidemic among Spanish males in the coming years, if this trend continues. For women, mortality rates were 5 to 9 times lower than those for men, 6.3 per 100,000 in 1973 and 6.4 in 1997. However, the increasing mortality among younger generations born since 1942 reflects the rise in the prevalence of smoking women during the last decades and can be expected to spread to older age groups as a cohort effect, indicating the early phase of the smoking-related lung-cancer epidemic among Spanish females. The decreasing mortality trend observed in women until the late 1980s could be attributed to a lower exposure to environmental tobacco smoke at home as a result of a significant reduction in the prevalence of smoking men. © 2002 Wiley-Liss, Inc.