Background:  Adolescence is aunique stage of human development and and an important tme for laying the foundations of good health. Adolescents experience rapid physical, cognitive and psychological growth. Aim of the study: Assess physical activity, behavioural and emotional changes among adolescents in nursing secondary schools at Beni-Sufe City. Research design: Across sectional descriptive research design will be used to achieve the aim of current study. Sample: all available adolescents in nursing secondary schools in the Village of Barout and Tzimant at Beni Suef. Setting: The nursing secondary schools in the village of Barout and Tzimant at Beni-Suef City. Tool: One tool used to achieve the aim of this study: Interviewing Questionnaire Sheet which consisted of four parts to assess personnel characteristics, family history and body mass index, knowledge about importance of physical activity, practice of physical activity and emotional and behavioral changes among adolescents. Result: The study showed that, 38.30% of the studied students had a good level of knowledge score, 66.5% of the studied students are physically inactive and 66.90 % of the studied students had a positive emotional and behavioral attributes. Conclusion: There was a highly positive association between studied students' total knowledge, physical activities and their emotional and behavioral attributes, that means increase student awareness regarding importance of physical activity will positively affect their practice toward physical activities and improve their emotional and behavioral changes. Recommendation: Further research about regular training program for adolescents to improve their knowledge regarding physical, behavioral and emotional changes. Increase awareness of students about importance of physical activity.