More and more, Intensive Community Treatment programs in Canada use questionnaires to evaluate the health and social functioning of individuals suffering from a severe mental illness. However, seldom are these tools subject to psychometric analyses to establish their validity on independent samples. This article presents the results of the validation of the French version of the Multnomah Community Ability Scale. Confirmatory factor analyses were carried out to assess the factorial structure. The factor structure, four dimensions with three items, emerging from a first sample was replicated with data from a different sample of clients. Moreover, these four dimensions respect the initial factor solution of the Multnomah Community Ability Scale, which are a) interference with functioning, b) adjustment to living, c) social competence, and d) behavior problems. The study shows the structural validity of this brief questionnaire, which could be useful both for clinical and research settings to evaluate the effectiveness of interventions.