Background and Aims In Australia, as in many countries, alcohol consumption increased dramatically during the second half of the 20th century, with increased availability of alcohol, relaxation of attitudes towards drinking and shifting roles and opportunities for women as facilitating factors. We sought to investigate drinking trends by gender and birth cohort in Australia during this period. Design Setting, Participants and Measurements Retrospective cohort study. Using the usual frequency and quantity of beverage-specific alcohol intake for 10-year periods from age 20, reported retrospectively from 40 789 participants aged 40-69 years (born 1920-49) at recruitment to the Melbourne Collaborative Cohort Study in 1990-94, we compared trends in alcohol consumption by sex in Australia between 1950 and 1990. Participants' average daily consumption for age decades were transformed to estimated intakes for 1950, 1960, 1970, 1980 and 1990. Findings Conclusions Alcohol consumption was higher for men than women during each decade. Alcohol consumption increased for both sexes in the 1950s, 1960s and 1970s, and fell after 1980. The rise before 1980 was roughly equal in absolute terms for both sexes, but much greater relative to 1950 for women. Women born during 1930-39 and 1940-49 drank more alcohol during early-middle adulthood (ages 20-40) than women born during 1920-29. In the 1980s, the fall was greater in absolute terms for men, but roughly equal relative to 1950 for both sexes. In both sexes, the decline in drinking in the 1980s for birth-decade cohorts was roughly in parallel. Specific birth cohorts were influential in the rise in alcohol consumption by Australian women born in 1920-49 after World War II. Much of the convergence with men's drinking after 1980 reflects large reductions in drinking among men.