Objective: To investigate lay peoples’ knowledge of health risks of overweight, accuracy of self-perception of body weight and perceived benefits of weight loss. Method: A nine item questionnaire was administered to a cross sectional survey of adults in metropolitan shopping centres, height and weight were measured. Results: Two hundred and nine (57% female) adults completed the survey. Thirty eight percent had a healthy BMI (18.5-24.9), 38% were overweight (BMI 25-29.9) and a further 22% were obese (BMI>30). However only 46% perceived themselves ‘overweight’, 50% considered themselves ‘just about right’ and 4% considered themselves ‘underweight’. Of those with a BMI of 25 or greater 28% considered their weight ‘just about right’. Over 80% thought ‘being overweight’ was ‘likely’ or ‘very likely’ to be a risk factor for cardiovascular disease, hypertension, diabetes and stroke; however 20% of overweight or obese individuals did not think their health would improve if they lost weight. Conclusion: A significant proportion of overweight or obese individuals do not accurately perceive their body weight and do not recognise the health advantages of weight loss despite recognising excess body weight as a risk factor for chronic diseases. Implications: Increasing the awareness of an individual’s BMI and promoting the benefits of modest weight loss maybe two underutilized strategies for population level weight control.