The Assessment of Social Self-Sufficiency (ASSS) is a scale of hetero-assessment, made up of seventeen items and five subsets, devised to investigate the self-sufficiency level of the persons who suffer from chronic psychiatric trouble. We know indeed that, for these patients, the success of their rehabilitation plans depends on their ability to face up to tangible problems in everyday life. This publication expounds the first work validating the ASSS. The "intercotators" accuracy of the work, its sensitiveness, its concurrent validity investigated with regard to the Global Assessment of Functioning Scale (GAF of the DSM III-R) as well as the inner contents seem to be very satisfactory.