Fundamental principles of the "Logotherapy and Existential Analysis", which was founded by FRANKL and further developed by LANGLE, are examined from the view of the Clinical Child and Adolescent Psychology with regard to theoretical aspects as well as to their practice-oriented relevance for the Child and Adolescent Psychiatry and Pediatry. Applying the "existential analytic diagnostic scheme" central subject-matters of finding the purpose in life as personal and existential basic motivations are considered in the differential-diagnostic proceedings and permits--as demonstrated by examples--a holistic consideration of specific problems. The indication of a functional, counseling-attendant or psychotherapeutic intervention depends on the impairment in the dimensions of personal and/or existential meaning-frustration. Finally the significance of personal attitude towards differential diagnosis as well as towards the motivation for therapy is emphasized, a criterion non considered in actual versions of international diagnostic schemes as ICD-10 or DSM-IV.