Objectives:: The objectives of this study were to determine the prevalence of sleep paralysis (SP) in medical students from the University of Buenos Aires (UBA). Materials and Methods:: An ad hoc questionnaire based on the diagnosis of SP and a demographic survey was electronically presented to students of Internal Medicine at the School of Medicine of the UBA. The respondents answered both questionnaires using Google Forms. Results:: The prevalence of SP was 40.7% (95% CI 33.547.8). A higher percentage of the respondents (76%) reported experiencing SP-related anxiety. An association between self-perceived quality of sleep and the incidence of SP was found (2: 12.712, P = 0.002). The highest frequency was hypnopompic SP (55.55%), and the highest percentage (55.4%) suffered from SP less than once every 6 months. Most respondents (59.5%) reported having started with SP symptoms after 18 years of age, and the highest percentage (66.2%) had exacerbated their symptoms at college. The frequency of the Incubus phenomenon was 14.5% (95% CI 6.223). Most respondents (70.8%) denied the association of SP with religious or paranormal beliefs. Conclusion:: SP is highly prevalent in medical students and is associated with poor sleep habits and perceived poor sleep quality. Clinicians should be aware of this parasomnia to avoid a misdiagnosis of psychosis and inform sufferers of the nature of SP.