The aim of the study was to determine the existing differences by gender in the indicators of internalizing problems regarding the body image perception of Mexican adolescents. A descriptive and transversal study was developed. The participants were students from four public middle schools in Guadalajara Mexico. The instrument used was an online survey constituted by a sociodemographic section, an internalizing problems indicators scale (α = .85) and a body image perception scale (α = .70). Parental consent was obtained using a waiver of active consent. The survey was applied online, during school hours at the computer labs. Descriptive statistics were calculated for the sociodemographic data and the body perception scale. Zscores were determined for the internalizing problems scale, being categorized into a three level rank. Statistical differences were estimated by gender using one-way analysis of variance (ANOVA). The sample included 2080 adolescents with a mean age of 13.6 years (SD 1), of which 51% (1059) were female and 49% (1021) male. 18.1% of the participants that describe themselves as about the right weight, followed by 13.9% that do it as slightly overweight, indicating that they are trying to lose weight. Regarding the differences by gender, 16% of the males and 17.9% of the females have high indicators of internalizing problems. Taking into consideration the body image, the males that describe themselves as very overweight and the females that do it as very underweight are the groups with higher indicators of internalizing problems. In summary, there are important differences between males and females in the internalizing problems indicators regarding the body image.How to cite this paper: Colunga-Rodríguez, C., Orozco-Solis, M. G., Flores-Villavicencio, M. E., de-la-Roca-Chiapas, J. M., Gómez-Martínez, R., Mercado, A., Vázquez-Colunga,