Background: Internet addiction has an unfavorable impact on dietary habits of adolescents. The aim was to assess the consequences of internet addiction on dietary behavior of adolescents in Assiut city. Design: Correlational descriptive research design was used in this study. Setting: Four governmental secondary schools in Assiut city were the setting of the study. Subjects: A representative sample of 400 adolescents was recruited for this study. A stratified sampling technique was used. Tools: Three tools were utilized to collect the data: Socioeconomic scale, internet addiction test, and dietary behavior and diet quality questionnaire. Results: More than one-third of the studied adolescents had occasional to frequent problem due to internet use and near to one-quarter of them had a significant problem from internet use. Also, they were skipping meals, snacking frequently, had a poorer appetite, and bad diet quality. Conclusion: Adolescent students who had significant problem from internet use had improper dietary behavior, a poorer diet quality than their counterparts who had control over internet use. Recommendations: Raising adolescents' awareness through mass media and health education program in schools and family-centered care about adverse effects of internet addiction on their development especially dietary behavior.