Very often, someone needs to make decisions in difficult situations of choice from several alternatives, using many criteria of different importance. Solving such problems requires the involvement of experts and a group expertise. One of the most important and challenging aspects of the expertise is the selection of highly qualified experts. The solution of this problem requires the use of adequate justified procedures assessment of experts’ quality. Nowadays, there is no unified approach to the concept of expert’s quality and the assessment procedure. The article describes the hierarchical assessment procedures of involved experts’ quality that consists of the methods of formation of the group expert judgements, including the rule of the accounting of weights, determining the quality of an expert, in the formation of the group expert judgments and assessment of private indicators of quality and the integral level of quality for involved experts. For assessment of the expert with the use of each of the particular properties that make up the concept of the quality of expert, appropriate methods of their determination are implemented.