At present, Psychological aspects have got much attention in all the spheres of life including the educational set up. Changing world's scenario have affected every walks of the human life. Not only the common and working people but students are also struggling with the multi facets problem of psychological disorders. That is why present study aims to assess the Psychological Well-being among Science and Social Science Under-Graduate students of Aligarh Muslim University, Aligarh, U.P. India. Ryff's Psychological Well-being scale was administered on a sample of 163 Under-Graduate (male=83, female=80) students of Science and Social Science Streams. In order to analysis of collected data; Mean, SD and t-test were applied. Findings showed no significant difference among the under-graduate students of science and social science with respect to Gender and Choice of streams. Findings of the study have its importance for the further studies, psychologists, counsellors, educationists, policy makers and so on. Further, issues of future studies have been discussed in the light of delimitations of the present study.