Objective: This study aims to evaluate the net benefits of psychiatric pharmaceutical care with shared decision-making (PCC-SDM) intervention in complicated schizophrenic patients for resolving drug-related problems (DRPs). Methods: Eligible inpatients for 3 months. Data were collected using an Integrated Hospital Medication Management with SDM (IHoMe-SDM) following PCC-SDM six steps: (1) data collection, (2) choice and option talk, (3) decision talk, (4) pharmaceutical care plan, (5) patients education, and (6) monitoring. Cost analysis was conducted by activity based costing. Economic evaluation was calculated as cost saving, cost avoidance, and net benefits with the view of health-care provider and reported in USD (THB). Results: Thirty patients were enrolled. There were 43 DRPs including non-adherence, adverse drug reaction (ADRs), drug interaction, and medication reconciliation (27, 13, 1, and 2, respectively). Total cost of the intervention was $192.35 USD (5810.93 THB). Total cost saving was $1626.63 USD (49,140.77 THB). Cost avoidance was $632.64 USD (19,112.00 THB). Net benefits were $2066.93 USD (62,441.84 THB). Clinical outcomes were the reduction of ADRs and readmission. Conclusion: PCC-SDM intervention among the patients with complicated schizophrenia offers a positive net benefits indicating that this program is an efficient choice for improving clinical outcomes of DRPs.