Resumo. ABSTRACT Sedentary behaviour is a global concern over the past decade and still an alarming issue at present. Among the concerns of being sedentary was gadget use among children as well as physical activity involvement. Several researches explore the factors link to inactive lifestyle. However, theory generation particularly on gadget use and physical activity involvement process among children were limited. Thus, this paper aims to build theory on gadget use and physical activity involvement among children. This study explores children experiences on too much gadget use and physical activity involvement through qualitative approach using grounded theory lens. Participants of the study were 11 to 13 years old school student and selected parents from Philippines. Data were gathered through face-to-face semi - structured in depth interview. Computer assisted qualitative data analysis (CAQDAS) was implemented in this study. Specifically, ATLAS ti. 22 software was used in data management and analysis which was guided by constructivist grounded theory by Charmaz. Theory was generated in this study after coding process i.e. initial coding, focused coding and theory building. Rigorous analysis of data in this study generated a theory and presented in form of process. The children’s involvement process theory to gadget use and physical activity was explained in the following phases; being influence, being happy, accepting the situation, giving conditional task, physical activity: being last on the list. The findings indicate the reason why children spend too much time on gadget as they interpret it as happy place and less time for physical activity as they consider it as last in engagement priority. Results of this paper contribute understanding on how middle school students interpret their experiences regarding excessive gadget use and physical inactivity. Awareness on how children view gadget use and physical activity involvement provides parents, health experts and other related professionals a basis for creating a plan or strategy to promote a balance gadget use and physical activity involvement for children.