Objective: The primary aim of the Scottish Schizophrenia Outcomes Study (SSOS) was to assess the feasibility and utility of routinely collecting outcome data in everyday clinical settings. Data were collected over three years in the Scottish National Health Service (NHS). There were two secondary aims of SSOS: first, to compare data from patient-rated, objective, and clinician-rated outcomes, and second, to describe trends in outcome data and service use across Scotland over the three years of the study (2002-2005). Methods: This study used a naturalistic, longitudinal, observational cohort design. A representative sample of 1,015 persons with ICD-10 F20-F29 diagnoses (schizophrenia, schizotypal disorders, or delusional disorders) was assessed annually using the clinician-rated measure, the Health of the Nation Outcome Scale (HoNOS), and the patient-reported assessment, the Avon Mental Health Measure (Avon). Objective outcomes data and information on services and interventions were collected. Data were analyzed with regression modeling. Results: Of the 1,015 persons recruited, 78% of the cohort (N=789) completed the study. Over the study period, significant decreases were seen in the number of hospitalizations, incidence of attempted suicide and self-harm, and civil detentions. Avon scores indicated significant improvement on all subscales (behavior, social, access, and mental health) and on the total score. However, HoNOS scores on the behavior and symptom subscales did not change, scores on the impairment subscale increased significantly (indicating increased levels of impairment), and scores on the social subscale decreased significantly (indicating improved social functioning). Conclusions: This study has demonstrated that it is feasible within the Scottish NHS to routinely collect meaningful outcomes data in schizophrenia. Patient-reported assessments were also successfully collected and used in care plans. This model shows that it is possible to incorporate patient-reported assessments into routine care for schizophrenia. Such assessments may provide useful data for clinicians and may improve treatment adherence. The pattern of outcomes and interventions confirms that despite the introduction of guidelines, new treatments, and new services, people with schizophrenia continue to have high levels of chronic disability.