Introduction: Basic Life Support (BLS) refers to the procedures that must be performed in situations of cardiorespiratory arrest or airway obstruction, and therefore, undergraduate students and health professionals must be highly trained to perform. Objective: To determine the level of knowledge about Basic Life Support (BLS) and the associated factors among undergraduate students from the health area in their last year of school in a public university. Methods: This is a cross-sectional study with undergraduate students in Physical Education, Nursing, Pharmacy, Medicine and Dentistry at the Universidade Estadual de Ponta Grossa, Brazil. Data collection was carried out in 2019, in the last month of course completion, by a trained researcher using a self-administered questionnaire containing sociodemographic data, professional training, perceived self-knowledge and a validated BLS instrument. There was an association between the outcome “undergraduate students’ knowledge” dichotomized as high (≥70% correct) or low level (<70% correct) and the independent variables (sociodemographic data, professional training and perceived self-knowledge) and the performance of the binary and multinomial logistic regression (p<0.05). Results: 191 undergraduate students participated in the study, being 85.6% of the chosen universe. A total of 30 participants (15.7%) had a high level of knowledge on BLS, being students from the Nursing (n = 12) and Medicine (n = 18) courses. While 35.3% of Nursing students and 46.2% of Medicine students had a high level of knowledge about BLS, there were no students from the Physical Education (0.0%), Pharmacy (0.0%) and Dentistry (0.0%) courses. In the crude analysis, the low level of knowledge was associated with younger age (OR=2.75, 95%CI:1.22-6.21), not feeling safe to perform BLS (OR=3.12, 95%CI:1.38-7.01) and the fact that the discipline was not part of the undergraduate course (OR=18.35, 95%CI:2.44-138.1). In the adjusted analysis, the fact that the discipline was not part of the undergraduate course (OR=13.41, 95%CI:1.74-103.12) remained. Conclusion: Most students had a low level of knowledge about BLS, and only students from the Medicine and Nursing courses demonstrated a high level of knowledge. After adjustment, the fact that the discipline was not part of the undergraduate course was associated with a lower level of knowledge about BLS.