This study drew upon the theory of reasoned action (TRA) to predict the intention to drive while intoxicated (DWI). Four hypotheses were tested using telephone survey data from a random sample of 1,259 adult residents of Bemalillo County, New Mexico. Results showed the TRA to be predictive across a diversity of social groups. Contrary to hypotheses, subjective norms were a more powerful predictor than attitudes, and the perceived severity of DWI penalties was positively correlated with DWI intention, a paradoxical result that was explained with reference to the social environment of likely DWI offenders. The results suggest that anti-DWI public-information campaigns should stress the importance of informal social influence against drunk driving, rather than merely the legal penalties for drinking and driving.