The study of gender stereotypes of physical activity in the textbooks of mentally retarded students is a vital issue because physical activity is related to the health of students. Based on this, the current research aims to answer the question “How is the teaching of physical activities in the textbooks of mentally retarded with emphasis on gender stereotypes?” done. For this purpose, this research has analyzed all the textbooks of the preschool and elementary levels of mentally retarded students, with several 46 books and 7664 pages, using the MaxQDI 2020 software, using the qualitative-quantitative content analysis strategy. For the open coding process, the content of the textbooks was carefully studied several times. Then the researcher has listed the information, keywords, images and explicit and implicit texts related to the teaching of physical activities with emphasis on gender stereotypes in textbooks as codes, and with the continuation of the study, he has categorized the codes with the axial coding method, until the codes similar to be placed in the same category. Also, the codes and data were compared to find similarities and differences, and finally, according to the results, categories, and subcategories were developed, to increase reliability, the agreement tool between coders was used. The obtained results show that in the textbooks, explicitly and implicitly, physical movement content with the gender of girls is less produced and there are gender stereotypes in the mentioned textbooks. So gender stereotypes in seven main categories; The type of physical activity, the place of physical activity, the purpose of physical activity, equipment for physical activities, clothing in physical activities, sedentary behaviors, and national sports personalities have been extracted. So girls were shown in a minimal variety of competitive activities and sports places. At the same time, reducing sedentary behaviors and increasing physical activities to have health and well-being and prevent diseases and premature deaths are necessary for both boys and girls with mental disabilities. This gender stereotype that physical activities are for boys and girls participate less in physical activities; can lead to the belief among mentally retarded girls that they cannot be active in physical activities like boys and may experience more sedentary behaviors as a result. So, to increase the health and reduce the threats of inactivity of girls with intellectual disability, there is a need to reduce it and confront the gender stereotypes for physical activity in the textbooks of mentally retarded students. Any gender discrimination in educational materials, which shows the unequal treatment of a certain gender, can also be transferred to new students.