Resumen: Introduction: The internal, vaginal or female condom is a barrier method made mainly of polyurethane, which has a sheath length of 17 cm and a diameter of 7.8 cm. It is used to have safe sexual practices, since, like the penis condom, they prevent pregnancy and reduce the risk of acquiring a sexually transmitted infection. Objective: To analyze knowledge and myths about the internal condom in people between 15 and 25 years of age in the provinces of Santiago, Melipilla and Talagante of the Metropolitan Region, Chile, in 2021. Method: A cross-sectional descriptive quantitative study was carried out with a sample of 5 females and 5 males, with a total of 110 participants. Results: It was obtained as a result that only 5% of the respondents (6/110) have used the internal condom; in contrast, the penis condom has been used by 79% of the participants (87/110). Regarding myths, 55% of the population (60/110) affirm that using both condoms increases their effectiveness. Conclusions: It is possible to conclude that factors such as age and level of sexual education influence the knowledge and myths that revolve around the internal condom.