Prior research indicates that adolescent boys are often more active than girls, implying a need for special attention to increase the physical activity levels of adolescent girls. Adolescents are at an age where they are especially susceptible to environmental and social influences but still have a limited amount of autonomy over their own behaviors. The effective physical activity programs implemented at this age may benefit health into adulthood. The fact that adolescents’ physical activity is influenced by many factors indicates that to achieve any behavioral change, interventions must target several levels across the socio-ecological model. During childhood, the family is the primary factor in socializing and shaping engagement in physical activity. This study is part of the Physical Education (PE) Homework Study project which was implemented in a midsized secondary school in the middle of Finland from 2016 to 2020. The goal was to develop one easily approachable way to prevent the decreasing physical activity of adolescent girls. This was done by increasing physical activity times of adolescent girls outside of the school by giving them active PE assignments. The aim was also to explore students’ and their parents’ perceptions of physically active physical education homework. In this part of the study, there were 43 interviews: 38 student interviews and 5 interviews with parents. The analysis process followed the qualitative content analysis (QCA) strategy by Schreirer. In this study, we combined the views of students and parents, and obtained a broad picture of the PE homework assignments given at school but completed at home. According to students and parents, PE homework assignments should be diverse, interesting, and challenging, they should also be provided at flexible schedules outside of school hours with family support. Physical education homework could be a potential approach to influence the physical activity of the student population by involving school curriculum and families.