The article considers the basic principles of professional ethics of educational experts in conducting institutional audits of educational institutions, including the rule of law, public interest as the main criteria of professional activity of an expert, professional competence, exclusion of self-profit actions, objectivity and independence, confidentiality of information, etc. The rules of interaction with representatives of educational institutions engaged in educational activities are presented. Emphasis is placed on the psychological aspects of business relations and relationships with colleagues. It is noted, that the work of an educational expert does not only require comprehensive knowledge of legislation in the field of education, but also includes certain moral obligations based on generally accepted norms, which guide the expert in conducting institutional audits in educational institutions. The Code of Professional Ethics of an institutional audit expert in educational institutions is a set of moral and ethical obligations and requirements based on generally accepted norms, which experts have to follow during the institutional audit procedure in educational institutions. The following theoretical research methods were used to solve certain problems: systematic analysis, comparison, systematization, classification and generalization of scientific and methodological literature on the problem; method of systematic analysis of philosophical, psychological-pedagogical, sociological literature for theoretical generalization of leading scientific approaches; interpretation of key provisions of the study.