This study focuses on Sustainable Development Goal (SDG) number 3, which promotes health and well-being. The overall objective was to determine the construction and psychometric properties of the Inventory of Prevalence of Sexist Thoughts in adolescents in the city of Trujillo, 2025. The research is descriptive in nature, with a methodological approach and a non-experimental, instrumental design. The sample consisted of 555 male and female adolescents from Trujillo, who were administered the Sexist Thoughts Prevalence Inventory (IPPS-25). The factorial analysis identified two dimensions: gender hierarchies and social identity, and affective and behavioral expectations toward the opposite gender. The confirmatory factor analysis confirmed that the two-dimensional model fits appropriately (CFI = 0.949, TLI = 0.939, SRMR = 0.048, RMSEA = 0.038). Convergent validity reflected a positive correlation with the external test, the Ambivalent Sexism Inventory (ASI). Likewise, adequate internal consistency was shown, given that the alpha coefficient is .719 and the omega coefficient is .749. Conclusion: The IPPS-25 psychometric instrument allows for the identification of the prevalence of sexist thoughts in the adolescent population in an ideal way.