Introduction: pre-exposure prophylaxis (PrEP) effectively prevents HIV in men who have sex with men (MSM). Chile recently incorporated PrEP as a strategy against HIV/AIDS. Despite its effectiveness, worldwide PrEP utilization among MSM is low. The theory of planned behavior (TPB) is one of the most popular psychosocial models used to predict and explain sexual risk behaviors. Objective: to analyze the intention to use PrEP among MSM using the TPB in Chile. Methods: 183 MSM were recruited online. The TPB constructs (attitude, subjective norms, behavioral control, and intention to use) were measured in addition to knowledge variables, sociodemographic aspects, and sexual risk behaviors. We use linear regression models to analyze the relationship between intention to use and other variables. Results: the perception of favorable social norms (B=0,356 p<0,01), higher perception of behavioral control (B=0,4 p<0,01), and positive PrEP attitudes (B=0,189 p<0,01) were significantly related to intention to use PrEP. Knowledge, the presence of sexual ri.sk behaviors, and sociodemographic variables were not associated with intention to use PrEP. Conclusion: the TPB contributes to understanding the intention to use PrEP in MSM in Chile.