Background: Internet use is one of the flourishing addictive behaviors and major public health concern affecting worldwide. University students have habit forming use of internet as well as its consequent negative effects. This study determined the prevalence of internet use, its addiction in medical students and its impact on depression, anxiety and stress levels of students by DASS-21 scale. Method: It is a cross sectional study done at NKPSIMS & RC & LMH, Nagpur, Maharashtra on 300 undergraduate medical students who consented for the study and chosen by simple random sampling. Self administered questionnaire was used to collect study data. Internet addiction measured using Young’s internet addiction test (IAT). Depression, anxiety and stress levels are measured by DASS-21. Result: Internet addiction was found in 02 % of participants. Maximum internet users visit social media applications and it is used least for educational purposes. Mobile phones are the most widely used devices to access the internet. Conclusion: Our study concluded that large number of students are using internet since long for non academic purpose with many of them having different levels of addiction resulting in negative impact on academics. Statistically significant relationship was seen between scores of IAT and Dass-21. Higher IAT scores were associated with poor academic performance and scoring, with higher depression anxiety and stress levels of students. Hence we recommend timely intervention of harmful consequences of excessive internet use. The association between internet addiction and its consequences should be dealt by undergoing more such studies.