OBJECTIVES: Management of patients with chronic relapsing schizophrenia is difficult and costly. We assessed the cost-effectiveness of paliperidone palmitate long-acting injectable (PP-LAI) versus risperidone depot (RIS-LAI), olanzapine pamoate (OLZ-LAI), oral olanzapine (oral-OLZ) and oral clozapine (CLOZ) from the viewpoint of the Finnish National Health Service. METHODS: We expanded and adapted a 1-year decision tree model that had been previously validated for Finland, with assistance from an expert panel. Patients started in a stable state and were treated as per standard procedures in Finland. Drug doses, success and relapse rates were determined from published clinical studies. Patient management was guided by expert opinion.  Health state utilities were derived from the literature.  Only direct costs were considered, including hospitalization and other institutional care, medical and nursing care, and drugs. Prices were obtained from standard lists. Outcomes included quality-adjusted life-years (QALYs), rates of rehospitalization and days with stable disease. The primary economic outcome was the incremental cost/QALY. One-way sensitivity analyses were performed on all pertinent costs and clinical inputs. Results between drugs were tested in a pairwise fashion with 10,000 Monte Carlo simulations each, using standard distributions for all variables. RESULTS: Expected costs were €10,691 for PP-LAI, €12,462 for RIS-LAI, €12,496 for OLZ-LAI, €27,270 for oral-OLZ and €23,258 for CLOZ. QALYs were 0.829, 0.813, 0.821, 0.739 and 0.523, respectively.  Rehospitalizations were 0.25, 0.30, 0.29, 0.61, and 1.88, respectively and days with stable disease were 329.3, 326.2, 325.1, 283.9 and 215.6, respectively. In the base-case, PP-LAI dominated all other drug choices. One-way sensitivity analyses indicated that results were insensitive to drug costs but sensitive to plausible changes in rates of adherence or hospitalization.  In probability sensitivity analyses, results were robust overall with ICERs significantly favouring PP-LAI (P<0.001). CONCLUSIONS: PP-LAI was cost-effective in Finland for chronic relapsing schizophrenia.