AbstractObjective:To evaluate weight misperception among adolescents and determine associations between self-perceived weight and socio-demographic characteristics, BMI, screen time, self-rated food quantity and diet quality, weekly frequency of breakfast and the consumption of healthy and unhealthy foods.Design:A cross-sectional, two-stage, probabilistic population-based study was conducted in Campinas, Brazil. Multinomial logistic regressions were run to estimate weight self-perception.Setting:Data from the Campinas Health Survey (ISACamp) and Campinas Food Consumption Survey (ISACamp-Nutri).Participants:A total of 911 adolescents aged 10–19 years.Results:Nearly half (47·7 %) of the adolescents with overweight/obesity did not evaluate their weight properly. Weight self-perception as thin and excess weight was associated with the female gender, overweight/obesity, self-rated diet quality as poor/very poor and eating snacks ≥3 times/week. Adolescents who did not consume breakfast daily were less likely to perceive themselves as thin. Adolescents who ate excessively were more likely and those who consumed cookies/crackers ≥3 times/week were less likely to perceive themselves as having excess weight.Conclusions:Greater weight misperception was found in overweight/obese adolescents. Gender, BMI, self-rated food quantity/diet quality, weekly frequency of breakfast and some unhealthy foods were associated with self-perceived weight. The present findings could contribute to health promotion strategies targeting adolescents.