Objective: The involvement of people with psychiatric disabilities in research and service evaluation has traditionally been rare, especially in the construction of outcome measures. This study documents a collaborative process with consumers from 2 Portuguese community mental health services in the construction of the Capabilities Questionnaire for the Community Mental Health context (CQ-CMH). The measure is inspired by Nussbaum's capabilities approach and aims to measure consumers' capabilities when supported by the community mental health services. Method: Focus groups with 50 consumers from 2 programs generated data about their gains from and goals for participation in the programs. A Steering Committee-comprising 3 consumers and 2 researchers-analyzed the data, generated a list of items, sorted them according to Nussbaum's list of capabilities, and developed a rating scale. To check face validity, the questionnaire was tested with 15 consumers. Results: The collaborative process led to the transformation of traditional research roles, the promotion of empowerment to participants, the ecological validity of the results, and a cultural adaptation of Nussbaum's list to the context of the study. The resulting CQ-CMH is composed of 104 items organized by 10 capabilities, and 1 open-ended question about service improvements. Conclusions and Implications for Practice: The capabilities approach and the collaborative process undertaken both support the exercise of choice and control by people with psychiatric disabilities. The capabilities measure-constructed by consumersmay be used as an outcome measure in service evaluation. The questionnaire will undergo further testing of its validity and psychometric qualities.