Introduction: A cross-sectional study was conducted to determine physical activity, eating behaviour, body weight management knowledge, perception of body image and their association with body weight status of adolescents. Methods: Respondents were 360 adolescents, aged between 13 to 14 years, from six randomly selected secondary schools in Kuantan, Pahang. Physical activity, eating behaviour, body weight management knowledge and perception of body image were measured by the Physical Activity Questionnaire for Older Children (PAQ-C), Eating Attitude Test-26 (EAT-26), Weight Management Knowledge Inventory (WMKI) and Contour Drawing Rating Scale (CDRS), respectively. Results: Almost half of the respondents were categorised as having a normal BMI, while 30.3% were severely thin and thin and 20.3% were overweight and obese. Mean physical activity score was 2.06+0.45 with more males (35.0%) being physically active than females (17.3%). Mean eating behaviour score was 15.41+10.37, with 27.8% of the respondents being at-risk for eating disorders. Mean weight management knowledge score was 5.35+1.80, with more females (77.7%) having higher mean scores than males (42.3%). Further, mean discrepancy score for body image perception was 1.24+0.99, with 78.1% of the respondents being dissatisfied with their current body size. Positive associations were found between eating behaviour (r=0.28, p<0.05) and body image (r=0.35, p<0.05) with BMI. Respondents with high eating behaviour scores and body image discrepancy scores were more likely to have greater BMI. Conclusion: This study shows the need for healthy eating and body image intervention programmes to prevent overweight and obesity problems among adolescents.