Medication non-compliance, a pervasive problem among persons with serious, chronic mental illness, has been linked to increased inpatient resources use in public mental health systems. The objective of this analysis was to determine which factors are associated with medication compliance in this population so that more appropriate screening and intervention programs can be designed. Using knowledge gained from clinical research on compliance in schizophrenia and research testing the Health Belief Model as a conceptual framework in studying compliance behavior, we conducted a secondary analysis of data collected in the Mississippi public mental health system in 1988. The study subjects were schizophrenic patients (n = 202), the majority of whom were low-income, African-American males. Data sources included structured interviews with patients and family members, as well as state hospital and community mental health clinic administrative records. Receipt of consistent outpatient mental health treatment and belief that one had a mental illness were significantly associated with higher levels of medication compliance in this population of seriously mentally ill patients. Our results suggest that screening programs to identify those at highest risk for non-compliance in this population might be more productive if they included a review of inpatient and outpatient mental health service utilization patterns, in addition to formal assessment of patients' attitudes and beliefs about their illness. This study illustrates an approach to examining predictors of a policy-relevant health behavior in a minority population within a public mental health system.