Background and Objectives: Despite the current literature on the importance of parental antismoking socialization messages, it is unclear if youths and parents agree on the content and frequency of such messages. This study's purpose is to explore the level of agreement between parents and youths on measures of anti-smoking socialization and to assess whether agreement is associated with parental smoking status and/or parental race/ethnicity. Methods: Data was collected from parent and 9- to 16-year-old youth dyads who presented to the emergency department with a non-urgent complaint. A self-administered questionnaire assessing demographics and five antismoking socialization measures was used. Results: Items that showed statistically significant agreement between parents and youths were frequency of explicit messages about smoking. However, the absolute agreement between the items was poor, at less than 50% for the complete sample. The following items did not show statistically significant agreement between parents and youths: maternal negative reaction to smoking (for all youths); specific rules about smoking and maternal negative reaction to smoking (for youths with parental smokers); and paternal negative reaction to smoking (for youths with parental nonsmokers). When pairs that did not agree were analyzed, we found significant discrepancies in youth-parent agreement by parental smoking status, but not by race/ethnicity. Conclusions: In this study, parents and youths had poor agreement on measures of antismoking socialization. Level of agreement was associated with parental smoking status, but not race/ethnicity. Since antismoking socialization is an important means to decrease youth tobacco initiation and use, future studies are needed to investigate the specific content, frequency, and format of parental antismoking messages that are best received and recalled by youths. (Contains 3 tables and 1 figure.)