OBJECTIVE:In Finland, regional rates of schizophrenia exceed those in most countries, impacting the healthcare burden. This study determined the cost-effectiveness of long-acting antipsychotic (LAI) drugs paliperidone palmitate (PP-LAI), olanzapine pamoate (OLZ-LAI), and risperidone (RIS-LAI) for chronic schizophrenia. METHOD:This study adapted a decision tree analysis from Norway for the Finnish National Health Service. Country-specific data were sought from the literature and public documents, guided by clinical experts. Costs of health services and products were retrieved from literature sources and current price lists. This simulation study estimated average 1-year costs for treating patients with each LAI, average remission days, rates of hospitalization and emergency room visits and quality-adjusted life-years (QALY). RESULTS:PP-LAI was dominant. Its estimated annual average cost was €10,380/patient and was associated with 0.817 QALY; OLZ-LAI cost €12,145 with 0.810 QALY; RIS-LAI cost €12,074 with 0.809 QALY. PP-LAI had the lowest rates of hospitalization, emergency room visits, and relapse days. This analysis was robust against most variations in input values except adherence rates. PP-LAI was dominant over OLZ-LAI and RIS-LAI in 77.8% and 85.9% of simulations, respectively. Limitations include the 1-year time horizon (as opposed to lifetime costs), omission of the costs of adverse events, and the assumption of universal accessibility. CONCLUSION:In Finland, PP-LAI dominated the other LAIs as it was associated with a lower cost and better clinical outcomes.