The article presents the results of the cardiovascular changes assessment using electrocardiography (ECG) monitoring during local anesthesia in GP dentists. Selective ECG monitoring was carried out in 60 dentists aged 25—55 years (1 group — 25—34 y.o.; 2 group — 35—44 y.o.; 3 group — 45—55 y.o.) by means of portable «Valens» system. The study of stress index or the index of regulatory systems tension (IT) was conducted for 6 hours in the first day half within 1 working day. IT from 50 to 150 relative units was considered normal. In the first group IT peak was observed at the time of expectation of clinically relevant anesthesia in upper and lower jaw, while in the second and third groups it was associated with pain reaction in the course of treatment despite of clinical signs of anesthesia in the maxilla (IT=20±5.3 and 231±1.4, correspondingly) and mandible (IT=213±2.7 and 223±2.6, correspondingly). In all groups greater IT correlated more with mandible anesthesia events.