Introduction: Cardiac arrest is one of the leading public health problems worldwide and in Brazil. A victim of cardiorespiratory arrest needs prompt basic life support (BLS) to increase survival. Objective: To evaluate the performance of a synthesis lecture on BLS given to university students in Health Sciences. Methods: A total of 422 undergraduate students in Nursing, Physiotherapy, and Medicine participated in this study. Data were collected by applying a pre-test through a BLS questionnaire based on the American Heart Association guidelines. Results: Students obtained a minimum grade of 40% of the pre-test questions. The score increased to 75% in the post-test; the students with the best performance in the pre-test maintained a higher total number of correct answers in the post-test. There was also better performance in those with previous training in BLS. The students from the first year of medical school were the ones who benefited the most from the lecture. Conclusion: Regardless of the grade course, the Health Science students showed a significant improvement in their level of knowledge after attending the synthesis lecture, indicating its adequacy to promote initial learning about BLS.