The objective was to analyze the effectiveness of Psychosocial Care Centers (PCCs) for persons with mental disorders in Pelotas, Rio Grande do Sul State, Brazil. This was a prospective cohort study with users of the centers, based on two home visits. Three treatment exposure variables and two health status variables were compared and stratified according to treatment modality and time attending the health service. We interviewed 1,013 patients on the first visit and 875 on the second. The most frequent diagnoses were mood disorder (39%), schizophrenia (24%), and neuroses (13%). More than 50% were receiving intensive or semi-intensive care, and nearly 60% had attended the center for at least three years. There was a significant reduction in crisis reports (p = 0.000) and fewer hospitalizations among those in intensive treatment (p = 0.002) and with longer time attending the center (p = 0.003). Among non-intensive patients, there was a decrease in the use of medication (p = 0.032) and increased participation in groups (p = 0.000). The Psychosocial Care Centers can be considered effective for persons with mental disorders.