Abstract: This study was conducted to determine the associations between body mass index (BMI), body weight perception and body shape among male and female adolescents. Besides, the aim of this study was to identify the differences in weight control behaviours between male and female adolescents. This cross-sectional study involved 194 subjects (98 males and 96 females) who were randomly selected from two secondary schools in Pulau Pinang. Subjects involved, were in the range of 16 and 17 years old. Information on socio-demographic, body image perception, body shape and weight control behaviors were obtained through questionnaires. Anthropometric measurements of body weight and height were also taken. Based on BMI categories (WHO, 2007), the results showed that 12.9% of the study subjects were classified as underweight, 55.2% normal weight, 17.5% overweight and 14.4% obese. The study found that the actual weight (BMI) of subjects were significantly associated to the body weight perception in overall and also for both sexes (p<0.05). There was a significant association between the selection of the current body shape and ideal body shape for both sexes (p<0.05). BSQ scores also showed a significant association with actual weight (BMI) for both sexes (p<0.05). This study showed that there was a significant association between males and females (p<0.05) based only on 2 out of 12 items of healthy weight control behaviors used in food diet and increasing physical activity. While for the 3 out of 9 items of unhealthy weight control behaviors used in skipping meals, starting the use of tobaccos and fasting, the study showed that there was a significant association between the sexes (p<0.05). Therefore, by understanding the reasons for gender differences in the actual weight and weight perceptions, it could assist health professionals in helping a person to make a strategic decision to control body weight thus could help avoid the risk of eating disorders.