OBJECTIVE: Outcomes for negative symptoms over a one-year period were examined in two groups of patients, one receiving psychoeducational multiple-family group treatment and one receiving standard care. METHODS: A total of 63 outpatients, ages 18 to 45 years, with DSM-IV diagnoses of schizophrenic disorders were randomly assigned to standard care or multiple-family group psychoeducation treatment at a large mental health center in Spokane, Washington. Treatment assignment was stratified by whether patients were taking typical or atypical antipsychotic medications. Negative symptom status was monitored monthly for one year by raters blind to group assignment and measured as a composite of five symptoms using the Modified Scale for the Assessment of Negative Symptoms. RESULTS: When the analysis controlled for baseline negative symptoms, participants in the multiple-family group experienced significantly reduced negative symptoms compared with those receiving standard care. Taking atypical antipsychotic medication or having a diagnosis of substance abuse was not associated with the severity of negative symptoms. An additional analysis of the five individual negative symptoms indicated small but consistent group differences on all dimensions except inattention. Negative symptoms were significantly correlated with relapse to acute illness but not with outpatient or inpatient service use. CONCLUSIONS: The study demonstrated that a psychoeducational multiple-family group intervention was more effective than standard care in managing negative symptoms over a 12-month period. The results are particularly relevant because negative symptoms are associated with relapse, poor social and occupational functioning, cognitive impairment, and lower subjective quality of life.