A transversal, descriptive study with an analytical component was conducted, aimed at evaluating anxiety during the period preceding the procedure, as well as hemodynamic and respiratory alterations and pain during the intraoperative period in patients undergoing the extraction of retained third molars under local anesthesia. Forty-two healthy male subjects, ranging in age from 18 to 34 years were included in the study. Anesthesia was performed with lidocaine hydrochloride 2% with epinephrine 1:50.000, at a dose ranging from 72 to 144mg. A non-invasive multiparametric monitor was used to monitor the following parameters: mean arterial blood pressure, heart rate, peripheral O2 saturation, respiratory rate; level of anxiety (anxiety scale for dental surgery) and pain (visual analog scale). Statistical analysis was performed with a paired Student's t and Wilcoxon's test. The significance level was set at 5%. In this study, twenty patients had some level of anxiety. Severe pain was reported in seven patients who required supplementation with local anesthesia during osteotomy, tooth sectioning and luxation. Individual analysis of hemodynamic and respiratory parameters showed alterations that were considered significant. The results of this study enabled us to conclude that hemodynamic and respiratory alterations may occur during the extraction of retained third molars. Monitoring is important for the detection and thus prevention of these complications. Furthermore, it is particularly useful in patients in whom these repercussions must be avoided.