Aims: The aim of the study was to identify heavy drinking trajectories from age 16 to 42 years and to examine their associations with health, social, employment and economic disadvantage in mid-adulthood. Methods: Finnish cohort study's participants who were 16 years old in 1983 were followed up at age 22, 32 and 42 (n = 1334). Heavy drinking was assessed at every study phase and based on these measurements trajectories of heavy drinking were identified. The trajectory groups were then examined as predictors of disadvantage at age 42. Results: Five distinct heavy drinking trajectories were identified: moderate (35%), steady low (22%), decreasing (9%), increasing (11%) and steady high (23%). Frequencies of the trajectory groups differed by gender. Using the moderate trajectory as a reference category, women in the steady high trajectory had an increased risk of experiencing almost all disadvantages at age 42. In men, increasing and steady high groups had an increased risk for experiencing health and economic disadvantage. Conclusion: Steady high female drinkers and steady high and increasing male drinkers had the highest risk for disadvantage in mid-adulthood. By identifying heavy drinking trajectories from adolescence to mid-adulthood we can better predict long-term consequences of heavy alcohol use and plan prevention and intervention programmes.