Background: Medical students confront significant academic, psychological, & existential stressors throughout their training. Objective: To find the prevalence of depression, anxiety and stress among the undergraduate medical students. Materials and methods: An institutional based cross–sectional study was done among the undergraduate medical students of Gauhati Medical College and Hospital, Guwahati from 1^st December 2017 to 31^st January 2018. Each of the students were given a questionnaire which consisted of two parts. Inclusion Criteria: 1) Students of all the semesters were included.2) Those who gave consent. Exclusion criteria: Those who did not fill up the questionnaire completely. Therefore, a total of 400 students were included in the study. The data was compiled using Microsoft Excel and Graph Pad INSTAT (Version 3.05). Results:There is a high prevalence of anxiety 164(41%) followed by depression 144(36%) and stress 127(31.75%) among the undergraduate medical students.