Background: Parents are the first line mediators in sexuality development of children. However, the majority of parents tend to have close supervision on children sexual behaviors, particularly in the conservative cultures. This article describes the development and psychometric evaluation of an instrument to measure Iranian parents’ competence in caring and nurturing their children sexually. Methods: The questionnaire was designed based on the principles in measurement, Waltz’stheory. The Iranian version of Children’s Sexual Behavior Questionnaire (CSBQ-IR) was developed and completed by 386 mothers and 101 fathers who participated in a community based sexuality education program in Tehran, capital of Iran. Reliability was assessed by Kuder-Richardson reliability coefficient and Split half. CSBQ-IR was evaluated for its construct, inclusiveness and content validity by principal component analysis. Results: The Kuder-Richardson reliability coefficient and Split half reliability were found 0.425 and 0.457 that was on acceptable range. Meaning, grammar, wording and item allocation of the questionnaire were found to be appropriate with (content validity ratio [CVR]=0.99) and(content validity index [CVI]=0.8) respectively. Conclusion: CSBQ-IR provides a valid assessment of the parents’ competency or incompetency in nurturing, communication, and managing their children’s sexual behaviors.