Background: The rationale of transmission prevention is related to transmission mechanisms, and evidence from observations has shown an improper use of personal protective equipment (PPE). Objective: We aim to describe the evidence on the transmission mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) and related prevention practices. Method: Review of the published literature on coronavirus disease 2019 (COVID-19) in the Scopus, Science Direct, and PubMed databases. Results: Transmission of respiratory viruses, including SARS CoV-2, could be by aerosols, droplets and contact with contaminated surfaces. Evidence suggests that the primary route of transmission of these viruses is by droplet and short distance. Scientific evidence in relation to the transmission of COVID-19 assigns the highest risk to the aerosol-generating procedures and by droplets in closed environments with poor ventilation, and the lowest risk of transmission by direct contact with contaminated surfaces. Conclusion: Prevention practices must be in correspondence with the evidence about the transmission of COVID-19, which will facilitate the rational use of available resources.