In order to provide a greater depth of information regarding the drinking and driving (DD) and riding with drinking drivers (RWDD) behaviors of young people, as well as their underlying causes, this article reports findings of a qualitative study investigating the influence of beliefs and expectancies on adolescents’ decisions to participate in DD and RWDD. The study consisted of 614, 15 to 20 year olds in the 9 counties of the greater San Francisco Bay area. A thematic analysis was performed. Study findings fall into four categories covering factors perceived as somewhat distal to the person, factors in the immediate social environment of the individual, other situational factors, and finally personal factors, covering the issue of perceived personal control. The focus was on the perceived impact of these factors on the decision to get involved in DD/RWDD or not. The study findings indicate that drinking and driving among adolescents is a very complex behavior. The inconsistencies revealed in the adolescents’ answers show that this is not a one-dimensional problem with one clear cause. Expectancies and control beliefs do not seem to influence the decision, whereas normative beliefs to some extent do. The findings indicate that increased enforcement of the laws may be helpful in preventing young people from getting involved in drinking and driving. References