Objective. To evaluate the effectiveness of FBT in comparison with usual care in people with schizophrenia treated at an outpatient psychiatric department of a public hospital in Chile. Method. Quantitative study, with a randomized, controlled clinical trial design (CTCT) and pre-post measurements, with two arms. Fifty-four people with schizophrenia and their primary caregivers, randomly assigned to experimental and control groups, were studied. The main outcome variable was social functioning. As secondary outcomes, clinical symptoms and treatment adherence in people with schizophrenia were evaluated. Expressed emotion was evaluated in the primary caregiver. Results. FBT was effective in improving the social functioning of people with schizophrenia and decreasing expressed emotion in the primary caregiver, with a large effect size (d > 0.80). Conclusions. The implementation of FBT as a protocolized intervention, complementing usual care, helps to improve psychosocial outcomes in people with schizophrenia and their caregivers.