This study aims to determine the process of creating the psychoeducational module for preventing child marriage for high school girls in Wajo Regency, Indonesia and to find out the product specification aspects of the psychoeducational module for preventing child marriage for high school girls in terms of the accuracy, feasibility and usefulness of the module. In order to answer the questions, the researchers used the RnD approach by compiling a psychoeducational module on the prevention of child marriage for high school girls which contained guidance programs and information about the effects of child marriage including efforts to prevent child marriage. In this study, the modules developed focused on developing skills or abilities to effectively undergo an important life transition, namely marriage. The results showed that the psychoeducational module for preventing child marriage was a form of development from an existing module which had gone through 7 stages including searching for potentials and problems, collecting data, product design, design validation, design revision, expert testing, and trial use. This module received a positive response from the aspects of its accuracy, feasibility, and usability. The results of the expert test showed that the accuracy of the module product gets a percentage of 91%, the feasibility aspect gets a percentage of 83%, and the usability aspect gets a percentage of 91%. The data from interviews showed that the contents of the module and its implementation can be accepted by adolescents aged 15-18 years and it can be also used by high school girls for guidance and learning. [For the complete proceedings, see ED672802.]