Background: Problematic internet use (PIU) is an emergent universal problem amongst students. The problem is growing in Egypt with the progressively mounting internet usage. Also, overweight of adolescents remains serious and alarming national and international health problem. Objective: To study the prevalence and coincidence of PIU, obesity and psychiatric disorders amongst students in governmental Egyptian high schools. Subjects and Methods: A cross sectional study was performed on randomly chosen 828 students from 2 governmental high schools in urban Gamalia town - Dakahlia governorate – Egypt.  Students were classified into theoretical educational group and scientific educational group. the students in each group were requested to fill Young Internet Addiction Test (YIAT) and General Health Questionnaire (GHQ-12) to assess problematic internet use and presence of psychiatric morbidity. Prior to that, sociodemographic data, medical reports and anthropometric measurements of the students had been obtained. Results: We noted that 12% (100 students) of the study candidates were obese, 24.3% (201 students) were overweight and 63.7% (527 students) represent normal and underweight adolescents. As well, it was found that 13.2 % (109 students) of the students were problematic internet users (PIUs). Prevalence of PIU was found higher among young ages, males and obese students. Also, students with higher father's educational degree, those who frequently use internet and those using internet for relieving loneliness, had a higher prevalence of PIU. Impaired relation with classmate friends with poor parents' satisfaction were also found in PIUs. The result also revealed that 31.9%   of the total students suffering from distress and 6.1% having severe problem and psychological distress. Also, our results showed that the PIU and psychological distress had a highly significant positive correlation [r (p-value) = 0.975 (<0.001)]. Similarly, a highly significant positive correlation was observed between PIU and body mass index (BMI) [r (p-value) = 0.914 (<0.001)]. Furthermore, a highly significant positive correlation was found between psychological distress and BMI [r (p-value) = 0.881 (<0.001)]. Conclusion: Problematic internet use and obesity are common and -associate each other- among high school students in Egypt which may affect their psychological health.