Misperception of body weight has become common in the global world and may affect motivation to lose weight particularly in overweight and obese subjects, leads to psychological distress. With the growing prevalence of obesity in Saudi Arabia, there is an urgent need of exploring the determination of serious epidemic. We investigate the prevalence of weight misperception with weight loss attitudes, behaviors’ and psychological distress in Saudi medical students. A cross-sectional study was conducted in primary care clinic at King Saud University Medical City during 2015-2016. In this study, 446 subjects were enrolled with an age range of 18-60 years of both genders. Data was collected by well-designed questionnaire and with International Physical Activity Questionnaire (IPAQ) and Kessler 10 scale (K10) for psychological assessment. The prevalence of misperception was 63.9%. Weight underestimation was present mostly in the female, young aged, married, high monthly family income and obese. There was a significant correlation between misperception and BMI (p ≤ 0.001). No association was observed in psychological distress, and weight misperception (p=0.258), and the effect of chronic diseases was a significant predictor of IPAQ (p ≤ 0.001). Misperception of body weight is common among Saudis. Although most of our studied population wants to lose weight, they had sedentary life style and imbalance diet. Understanding the cultural context of obesity in Saudi community and targeting misperception may facilitate the advice of healthy lifestyle behaviors and improve the effectiveness of obesity interventions.