| Background: This study sought to analyze differences in externalizing problems among adolescents in northern Chile in a pandemic context. Method: A recurrent cross-sectional design was used. The sample consisted of 475 students from educational establishments in the city of Arica, aged between 12 and 18 years. Externalizing mental health problems were measured before and after the COVID-19 pandemic. Results: The findings indicate a decrease in aggressive behaviors and an increase in attention and hyperactivity-impulsivity problems. In addition, contextual issues and the COVID-19 pandemic are factors that may impact the increase in externalizing problems, according to multiple linear regression models. Conclusions: The observed increase in some of the externalizing problems requires improved coordination and integration of mental health professionals in educational institutions.