Several studies have shown that a significant number of parents whose children have baby bottle tooth decay (BBTD) admit prior knowledge regarding the harmful effects of putting their children to bed with a bottle. The Elaboration Likelihood Model of Persuasion (ELM) offers a theoretical framework for better understanding why knowledge and attitude are often not predictive of behavior. The goal of this study was to use the ELM to analyze the manner in which information about BBTD is evaluated. One hundred twenty low-income women (either pregnant or with a child younger than 7 months of age) at a WIC clinic were randomly assigned to three groups: 1) 5-min audiotaped persuasive message about BBTD; 2) same audiotaped message with overheard audience response affirming the message; and 3) no intervention control group. Knowledge and attitudes about BBTD were measured before and after the experimental intervention. Participants hearing the audiotaped message also were asked to rate the expertise of the messenger and the quality of the message. Both groups hearing a taped message about BBTD showed a significant positive change in attitude and knowledge when compared with the control group (P < 0.05). No significant difference was found between the attitude and knowledge of those who heard an audiotaped message accompanied by an audience response compared with those who heard the audiotaped message alone. No significant difference between the ratings of message quality or messenger expertise by group was found. It was concluded that the participants in this study processed the BBTD message primarily through the central route, that is, by careful evaluation of the issue-relevant information contained in the persuasive message.