 Background: Anti-psychotic medications are an essential component of the treatment of patients with schizophrenia. Unfortunately, pharmacy data indicate that 40 of VA patients with schizophrenia are poorly adherent with their antipsychotics. These patients are at much greater risk for hospitalization. Objectives: We are examining the effectiveness of a practical, pharmacy-based intervention for improving antipsychotic adherence among patients with serious mental illness SMI. Specifically, we are examining whether this pharmacy-based intervention increases antipsychotic medication adherence and patient satisfaction with care and decreases psychiatric symptoms, and inpatient utilization. We are also examining the relative effectiveness of the pharmacy-based intervention among patients with varying: a degrees of cognitive limitations, b degrees of insight into their illness, and c attitudes towards their medications. Methods: Using pharmacy and administrative data, we are identifying patients with schizophrenia, schizoaffective disorder, or severe bipolar disorder requiring antipsychotic medication who have had poor antipsychotic adherence in the previous year. Patients must have completed at least two outpatient psychiatric visits at one of the study sites. Patients are randomized to: 1 usual care; or 2 the Pharmacy Based intervention. The pharmacy-based intervention consists of usual care plus: 1 unit-of-use adherence packaging; 2 a patient education session; 3 refill reminders; and 4 clinician notification of missed fills. In-person patient assessments are conducted at baseline, 6 months, and 12 months following randomization. Medical record and administrative data will be collected at baseline, 6 months, 12 months, and 18 months following randomization. The primary outcome measure is medication adherence as measured by the medication possession ratio and adherence categories which combine pharmacy information with patient self-report and antipsychotic blood levels. Patients level of psychiatric symptoms, quality of life, and satisfaction are secondary outcome measures. In supplemental analyses, we will compare the effectiveness of the pharmacy-based intervention among subgroups of patients who have varying degrees of cognitive limitations, insight into their illness, and attitudes towards antipsychotic medication. Findings: One hundred and fifty patients have been enrolled in the study. Follow-up rates have been high, with 90 of patients completing 6 month follow up assessments and 80 completing 12 month assessments. In person follow up visits are now complete. 