Background: Mobile phones have become increasingly popular in recent years, especially in young generation. The dependence on the mobile phone is increasingly high. At the same time, this new information and communication technology cause harm. Aim of the study: Assess mobile phone usage among adolescents in Zagazig City: patterns, dependency and perceived health risks. Subjects and methods: Research design: Cross sectional descriptive design was utilized. Setting: The study was conducted at preparatory and secondary schools in Zagazig city from both East and West administration. Subjects: The current study enrolled 870 of adolescent by using stratified multistage cluster sample. Tools of data collection: A self- administrated questionnaire sheet composed of four parts was used; the socio demographic characteristics, usage patterns, dependency and mobile phone related health risks. Results: The results of present study revealed that internet browsing (53.7%) was the most favorite feature of mobile phone use. Meanwhile, 9.2% of adolescents were severely dependent on their mobile phone phones; headache (47.4%) and tinnitus (40.5%) were the common complains. In addition to, moderate uncomfortable pain especially at the neck and slightly uncomfortable pain of different areas of the hands. Conclusion: Begin in secondary school increased the level of total mobile phone dependency. Recommendation: Seminar, conferences and workshops should be held to raise adolescents‟ awareness about mobile phone dependency and related health risks