Aims: Swedish smokeless tobacco (snus) is a lower-risk tobacco product than cigarette smoking for individuals. However, the public health impact of snus use is less well studied. Critically, it is uncertain whether use of snus leads to the onset of smoking. This study aimed to investigate prospectively the association between snus experimentation in late adolescence and daily cigarette smoking in early adulthood among Finnish young men. Methods: Data were obtained from 1090 young men within the population-based FinnTwin12 cohort. At baseline (mean age 17 years), we assessed lifetime use of cigarettes and snus, plus other potential predictors of cigarette smoking. At follow-up (mean age 24 years), participants were categorized according to their current smoking status. The final analyses were conducted among 375 young men who were never smokers at baseline with adequate data on follow-up smoking status and other potential predictors of cigarette smoking. Results: Age-adjusted logistic regressions showed an increased risk of becoming a daily smoker at follow-up among those participants who had at least tried snus but had never smoked cigarettes at baseline (odds ratio (OR) 6.48, 95% confidence interval (CI) 2.02–20.7), compared with those who had never used snus. When additionally adjusted for monthly alcohol intoxication, maternal smoking, and peer drug use, the association between snus experimentation and later daily cigarette smoking was attenuated, but remained significant (OR 3.94, 95% CI 1.22–12.7). Conclusions: Our data support the proposition that snus experimentation during late adolescence is longitudinally associated with daily cigarette smoking in early adulthood. Although a causal association cannot be inferred with certainty, snus experimentation might constitute an indicator of the propensity to proceed to regular snus use and initiation of use of other tobacco or nicotine products.