Abstract: I analyze the impact of timing of onset of marijuana use in youth on educational outcomes, distinguishing between general and vocational education. Using the Swiss Health Survey (2002) and a generalized ordered logit model for the estimations, I find some evidence for harmful effects of early marijuana consumption on educational success. Respondents who started to use marijuana before age 15 are significantly less likely to have at least a general secondary-level education, general tertiary-level and vocational secondary-level education. Those who started to use marijuana between age 16 and 18 are more likely to have a secondary or tertiary-level general education than those who never used the drug. The effects differ between those in general and those in vocational education, suggesting that the differences in institutional setting and time horizon between the two different educational tracks might lead to different effects on educational outcomes.