Obesity is a lifestyle disease that has been significantly increasing in the recent years. Body mass index (BMI) is recommended by the WHO to classify obesity and is used as a tool to identify patients or individuals at risk for adverse health outcomes. Waist circumference (WC) is also an important risk factor for lifestyle diseases and it can also be used to measure body fat distribution. Our study, therefore aims to determine the prevalence of overweight and obesity among the preclinical students in a Malaysian medical university, correlate the relationship of BMI and WC and evaluate the knowledge and perception of obesity of obese and overweight students. Method: A descriptive cross sectional study was performed involving 93 second year medical students. The BMI and WC were recorded of all the participants. The obese and overweight participants were identified and asked to answer a close-ended self-administered questionnaire. Results: Out of 93 students who participated in the study, 23 (25%) were overweight and 21 (22%) were obese. Pearson correlation analysis between BMI and WC values showed that the two variables strongly correlate with each other. The questionnaire identified gaps in the knowledge of the students and poor perception among overweight students. Conclusion: Hence, our study concludes that the prevalence of obese and overweight individuals is on the rise and there a gap in the knowledge. Based on our study results it is recommended that appropriate measures are taken to address the issue.