Prevalence of cigarette smoking among successive cohorts of Italian males and females born between 1890 and 1969 was estimated from data of the 1983 National Health Survey (based on 89,765 persons randomly selected within strata of geographical area, size of place of residence, and size of household), opportunely corrected for excess mortality of smokers. The overall participation rate for the original sample was 93.6%; impossibility of tracing or refusal of the interview led to substitution of 2,058 households. Among males, smoking prevalence in the young and middle-aged increased steadily up to the generation born in 1920-1929, which, in its 30s, showed the highest absolute smoking prevalence (68.3% in 1960). Moderate declines followed, chiefly on a calendar-period basis (i.e., between 1970 and 1980 in each birth cohort). These declines occurred later and at a lower rate than in several other Western countries. Among females, cigarette smoking was extremely rare for those generations born at the turn of the century (only about 3% of Italian females born in 1890-1899 ever smoked), but increased steadily in each birth cohort and calendar period to reach a rate only about one-third lower than that of males in the 1960-1969 cohort.