Background : Health related practices such as lifestyle patterns are important predictors of future health and since medical students represent a significant community investment so any information that may help us to promote their health will preserve this investment.Aim of the study: To throw a light on the differences in knowledge and practices regarding dietary habits and healthy lifestyle among medical and non-medical students in Baghdad along with assessment of any perceived barriers.Subjects and methods: This cross-sectional study included 350 students from 6 colleges, three medical and three non-medical colleges, in the period between 10th of February till 20th of May 2012.Simple random sampling was used in the selection of the colleges and students. Data was collected by direct interview using a questionnaire which was employed to assess knowledge and barriers to healthy practices among the students. Results: The knowledge score of medical students was better (with 94.7% of the medical students scoring good>17versus52%) than non-medical students. Conversely the diet and lifestyle score (36- point scale) in medical students was poor (<27) in 65.9% of them and in non-medical students was fair (27-31) in 57.2% of the students. ‘Lack of time’ was cited as the most important reason for skipping meals and as a barrier to exercising regularly, among both groups.Conclusion: The knowledge and practices of medical students in Baghdad suggest that superior knowledge about healthy lifestyle does not necessarily result into better practices.