Purpose: This descriptive study aimed to determine perceptions of adolescents about their weight and practices to lose weight. Methods: A convenience sample of adolescents (n=703) in grades 9 through 12 completed a questionnaire assessing demographic characteristics, perceptions about their weight, practices to lose weight and their information sources for losing weight. These students were then weighed and had their height measured. Body mass index (BMI) was calculated. Results: According to the measured BMIs, 11.2% of students were underweight, 74.1% were a healthy weight, 6.4% were overweight and 8.2% were obese. Of the adolescents, 13.1% perceived themselves as underweight, 65.0% perceived themselves as having a healthy weight, 19.7% perceived themselves as overweight, and 2.2 % perceived themselves as obese. There was poor agreement between measured BMI and adolescents’ perceptions (p < .05). Of the adolescents, 33% had tried/were trying to lose weight. Conclusion: The study determined that there are differences between the real weights and self-perceived weights of adolescents. School training programs should include information on proper body weight and form, and healthy methods of weight loss.