The main objective of this study was to evaluate the prevalence of emergencies in dental practices and the prepared-ness and the training experience in cardiopulmonary resuscitation (CPR) of Brazilian dentists in dealing with emergencies. The volunteer participants in the study were 498 Brazilian dentists who were present at the 27th International Congress of Dentistry in São Paulo. The most prevalent emergency was presyncope (reported by 54.20 percent of respondents), followed by orthostatic hypotension (44.37 percent), moderate allergic reactions (16.86 percent), hypertensive crisis (15.06 percent), asthma (15.06 percent), syncope (12.65 percent), angina (6.82 percent), convulsion (6.22 percent), hypoglycemia (5.62 percent), hyperventilation crisis (5.22 percent), choking (2.20 percent), and cerebrovascular accident (0.8 percent). Anaphylaxis, myocardial infarction, and cardiac arrest were the rarest emergencies, reported by only 0.4, 0.2, and 0.2 percent of dentists, respectively. Only 41 percent of the dentists judged themselves capable to diagnose the cause of an emergency during a dental visit. The majority responded that they would be capable of performing initial treatment of presyncope, syncope, orthostatic hypotension, convulsion, and choking. However, most of them felt unable to treat anaphylaxis, myocardial infarction, or cardiac arrest. Further, the majority felt unable to perform CPR or undertake an intravenous injection. It was concluded that the most prevalent medical emergencies in dental practice of Brazilian dentists are presyncope and orthostatic hypotension. The occurrence of life-threatening medical emergencies like anaphylaxis, myocardial infarction, cardiac arrest, and cerebrovascular accident is rare. Brazilian dentists are not fully prepared to manage medical emergencies and have insufficient experience training in CPR.