Dream analysis is the main road to the unraveling of the unconscious, but in the course of dream analysis some patients show attitudes referable to a deep-seated ego disturbance which had manifested itself in no other situation. Thus the patient's behavior during dream analysis may, under favorable circumstances, become an important clinical index of the nature and depth of an ego disturbance which would otherwise become apparent at a much later point of the analysis. Three instances are reported which illustrate this point. The question, why the hidden structure appeared for the first time in the process of dream analysis and not in other situations, is not investigated but the authors believe that in some patients the degree of ego modification, to which Freud attributed the main therapeutic obstacle, can be ascertained by attitudes which appear only during dream analysis in the early phases of the treatment.