Both in research and in practice, a number of basic competencies are considered necessary for successful process-oriented coaching and consulting activities. In the present research work, the extent to which these necessary competencies are related to vertical personality development was investigated. Loevinger''s model of ego development, a stage theory of development, provides the frame of reference for this study. This paper fully summarizes the current state of research on the model in order to comprehensively analyze possible relationships with coaching and consulting competencies. As a first step, the competency requirements of selected coaching and consulting associations were analyzed to determine whether they are related to ego development and whether they express minimum requirements for ego development. The analysis revealed that the competency requirements of all associations show clear parallels to aspects of ego development. The majority of these requirements point to a fully developed, self-governed stage (E6) of ego development as a prerequisite for process-oriented coaching and consulting services. In a second step, empirical studies were examined to systematically analyze the relationship between ego development and aspects relevant to coaching and consulting. The results of the current empirical studies show a clear correlation between these competencies and ego development. This means that as ego development increases, higher coaching and consulting competencies become more likely. Many studies also indicate that a fully developed, self-governed stage of ego development can be expected as the basis for consistent work at an intermediate level of competence.