ABSTRACT.Objective: The present study tested reciprocal associations between drinking-and-driving behavior and cognitions as youths transition to driving independently. We hypothesized that experience with driving and experience with drinking and driving would effect changes in cognitions about drinking and driving over time. We also tested cognitions as predictors of later drinking-and-driving behavior. Method: Two hundred and two high school youths completed mailed questionnaire measures at two time points, approximately 8 months apart. Questionnaire measures assessed youths' drinking-and-driving behavior, riding with a drinking driver, drinking-and-driving attitudes, normative beliefs, and perceived negative consequences at both time points. Results: Consistent with hypotheses, prior drinking-and-driving experience infl uenced changes in drinking-and-driving cognitions. Youths with drinking-anddriving experience at Time 1 saw drinking and driving as more dangerous over time; however, they perceived their peers as more accepting of this behavior. Time 1 attitudes predicted increased drinking-and-driving frequency at Time 2, and normative beliefs predicted increased frequency of riding with a drinking driver. Conclusions: These results support reciprocal associations between drinking-and-driving cognitions and behavior. Results of this study may have implications for the timing and content of drinking-and-driving interventions to reduce drinking and driving as well as riding with a drinking driver. , young drivers consume a greater amount of alcohol before driving and consider it safe to drive at higher blood alcohol concentrations than older drivers (Hingson and Winter, 2003). Compared with older drivers, youths are also at increased risk for alcohol-related traffi c crashes (Keall et al., 2004;Zador et al., 2000). Given this, it is important to understand risk processes that can infl uence and maintain youths' drinking-and-driving behaviors.The present study examines reciprocal associations between drinking-and-driving behavior and cognitions as youths transition to driving independently. Cognitive factors, such as attitudes and normative beliefs, are conceptualized as signifi cant antecedents of health risk behaviors in general (e.g., Ajzen and Fishbein, 2005;Sturges and Rogers, 1996) and substance-related behaviors in particular (Petraitis et al., 1995). However, there is also ample evidence from laboratory (Olsen and Stone, 2005) and longitudinal (Gerrard et al., 1996;Smith et al., 1995a) studies that engaging in a behavior can infl uence cognitions about that behavior. Reciprocal infl uences over time are an important component of developmental models of risk for externalizing problems in youths (Dodge and Pettit, 2003).Adolescent driving behavior can provide an ideal platform for examining reciprocal associations between cognitions and behavior. For youths, obtaining a driver's license is an important developmental transition, which can infl uence both the frequency and context of substance involvement (...