Background: Sexual education is one of the required and challenging areas for empowering families. It seems necessary to use appropriate tools in identifying and promoting the sexual education of parents. Objectives: This study aimed to investigate the construction and psychometric characterization of the Family-oriented and Developmental-based Sexuality Education Questionnaire for Iranian families. Methods: In this descriptive and survey research, the statistical population included all Iranian families in 2021. A number of 1,024 people throughout Iran were selected as the research sample using online sampling. The data were gathered through the Parental Sexual Education Style Questionnaire (PSESQ), Parental Self-efficacy Scale (PSES), and Family-oriented and Developmental-based Sexuality Education Questionnaire (F&DSEQ). The data were analyzed using Cronbach\\\'s alpha coefficient, correlation coefficient, and exploratory factor analysis in SPSS 26 and AMOS 24 software. Results: Three factors were extracted from the exploratory and factor analysis, including eleven factors in three general factors (sexuality education knowledge, attitude, and skills). These eleven factors could explain 58.319% of the variance in 58 items of the questionnaire. Cronbach\\\'s alpha coefficient was 0.92 for the whole questionnaire. Also, Cronbach\\\'s alpha of the components was in the range of 0.65 to 0.92. Conclusions: The Family-oriented and Developmental-based Sexuality Education Questionnaire has good reliability and validity and can be used to measure sexuality education knowledge, attitude, and skills. Therefore, F&DSEQ can be used in research, care, and educational interventions by specialists in the fields of nursing, midwifery, psychology, and family counseling.

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