Introduction: Self-medication is a common practice to alleviate symptoms of various diseases, in the child population such as pharyngitis and rhinopharyngitis that are common in health centers in Peru. Objective: To determine the factors associated with self-medication in children with upper respiratory tract diseases. Material and methods: Analytical cross-sectional observational study. The sample size was 206 parents who went with their children to the Emergency service. A questionnaire approved by Valenzuela M was used. and the SPSS program to find the frequency, the bivariate analysis and the multivariate analysis of Poisson logistic regression. Results: The prevalence of self-medication in children was 91,3%. Parents who only studied primary and secondary school were more likely to self-medicate their children PRa=1,22 (95% CI: 1,01-1,40). the first-born were protected from self-medication PRa=0,86 (95% CI: 0,76-0,97). Parents who were between 20 and 29 years of age obtained PRa=1,04 (95% CI: 0,96-1,13), children under 7 years old, PRa=0,99 (95% CI: 0,91-1,07) and parents of family that had 1 child PRa=1,04 (95% CI:0,90-1,20). Conclusions: The educational level and the order number of the child, such as being the first-born, had a significant association with self-medication in children.