The professional activity of a doctor focuses on the intersection of clinical knowledge and ethical principles. Meanwhile, medical ethics establishes the value and ideological foundations of the profession, whereas deontology serves as a tool that implements the principles within particular standards and rules of behavior. The contradiction between the importance of ethical and deontological regulators and the lack of empirical data on their relationship to the psychological characteristics of the doctor’s personality makes the study relevant. The aim of the paper is to study the relationship between deontological competence of a doctor and communicative competence, metacognitive characteristics and socio-psychological attitudes. 72 internists participated in the study (the average age was 48.5 years; the average proven record was 21.6 years). The methods of diagnosis of communicative competence, metacognitive knowledge and activity, social and psychological attitudes, as well as the author’s methodology for assessing deontological competence were used. Statistical processing included correlation analysis using the r-Spearman coefficient. Significant positive links of deontological competence with communicative ideals, metacognitive knowledge, metacognitive activity, concentration, choice of main ideas, time management, focus on altruism, as well as negative links with focus on selfishness and material values have been established. Deontological competence is an integrative education that combines value-semantic, reflexive-regulatory and motivational components, which allows it to be considered as a key mechanism for the implementation of ethical principles in clinical practice.