Objective To determine the perception of Almethnab town secondary school male students towards their body weights. Methodology We surveyed male secondary school students in Almethnab town in Qassim using a self-administered questionnaire and weighing/height scale. All of the four secondary schools were targeted. The calculated sample size was 256 students. A stratified cluster sampling technique was used to select research participants.Body mass index (BMI) was calculated and interpreted using web-based CDC childhood and adolescent BMI calculator. Weight status perception was assessed by comparing students' opinions about their weight against BMI percentile status. Results Out of 363 selected students, all of the available 270 students participated, with a response rate of 74%. Thirty-two (12.2%) of the students were underweight, 143 (54.6%) were normal, 30 (11.5%) were overweight, and 57 (21.8%) were obese. Students perception towards their weight was correct for 159 (65%) of students. Out of the 87 overweight/obese students, 16 (18.4%) perceived their weight as appropriate, 17 (53.1%) of 32 underweight students look at their bodies as normal, while 29 (20.4%) of normal weight students perceive themselves as overweight. Obese students exercise less both in frequency and duration than non-obese ones. Sweetened drinks, fast food and frequent snacks are weakly associated with obesity. Conclusion Prevalence of obesity is very high among male secondary school students in Almethnab town.One-third of students have misperceptions about weight status.