The etiology of homeless men (men without SR in the field of living & working) is studied by several sci's. A review of literature shows the following approaches: (1) psychobiological-the influence of physique & instincts; (2) psychol'al-character, regression etc; (3) psychiatric-deviant behavior is a manifestation of abnormalities in the structure of personality; (4) sociol'al-homelessness has its roots in soc org. Each approach is seen as inadequate by itself. There is a need for an interdisciplinary approach to the interaction of the above factors. These should be investigated by statistical-clinical res on homeless men. AA.