Tehran University of Medical Sciences Health Technology Assessment in Action 2645-3835 7 1 2023 07 19 169 169 Samira Atefifar Department of Educational Psychology, Qaenat Branch, Islamic Azad University, Qayen, Iran. Mohammad Reza Asadi Younesi Department of Psychology, Faculty of Educational Sciences and Psychology, University of Birjand, Birjand, Iran. Majid Pakdaman Department of Psychology, Qaenat Branch, Islamic Azad University, Qaenat, Iran 2023 05 08 2023 05 30 Background: Considering the expansion of friendship between boys and girls during adolescence as abnormal behavior in our society and the important role of communication patterns in the family, it is important to investigate the effect of mediating variables on this social phenomenon. Objectives: The present research has investigated the model of communication with the opposite sex among teenage girls in Birjand city under the influence of communication patterns in the family and the mediating variable of assertiveness. Methods: This is a correlational study. The sample size was 360 female students of Birjand city. The sampling method was multi-stage cluster random sampling. The data collection tool was a set of questionnaires. We use correlational analysis methods and Structural Equation Model to interpret data. Results: The fitted model showed that family communication patterns have a significant effect on the relationship with the opposite sex through mediating variables. Conclusions: The communication pattern of dialogue alone does not play a role in the relationship with the opposite sex, but with increasing assertiveness; it decreases the relationship with the opposite sex. https://htainaction.tums.ac.ir/index.php/hta/article/view/169 https://htainaction.tums.ac.ir/index.php/hta/article/download/169/121