Background: Use of the Internet, computers, smartphones, and other electronic devices has dramatically increased over recent years, and this increase is associated not only with tremendous benefits to the users but also with documented cases of excessive use, which has negative health consequences. In many countries, the problem has reached the magnitude of a significant public health concern. Objective: This study aimed at estimating the prevalence of Internet addiction among Egyptian medical students and its relation to their depression, anxiety and stress. Results: Across sectional study including 678 medical students. Their age ranged from 17 – 24 years, 41.4% of them were males. The participants were subjected to a self-administered questionnaire that included personal data, family history and their previous year academic degree, compulsive Internet use scale (CIUS) was used, and also Depression Anxiety Stress Scale-21 (DASS -21) was used for assessing anxiety, depression, and stress. Problematic Internet use (PIU) among the participant students was 68.3%, PIU was significantly associated with increased family income, depression, anxiety and stress were also associated with PIU with odds ratio [1.57 (1.11 – 2.22), 1.65 (1.11 – 2.43), 1.48 (1.03 – 2.12)] respectively. Conclusion: The high prevalence of problematic internet use (PIU) among medical students in Menoufia University is a matter of concern that is also associated with stress, anxiety, and depression as well as its negative impact on their academic achievement. It is important to plan comprehensive programs to raise public awareness about the hazards and introducing awareness and treatment services in primary health care facilities.