Schizophrenia is ranked among the top 25 leading causes of disability worldwide in 2013 which resulting in social and economic burden. By observing patients with schizophrenia one year before and after switching from oral antipsychotics (OAPs) to once-monthly paliperidone palmitate (PP1M), we can better understand the change of total costs in schizophrenic patients, including direct costs and indirect costs, after switching treatment patterns.A total of 100 schizophrenic (ICD-10) patients from Shandong Mental Health Center were collected from December 2016 to June 2019. Treatment modalities, health care resource utilization and costs were compared before and after switching directly from oral antipsychotics to PP1M.Of the 82 patients included in the main analyses, treatment with PP1M resulted in an increase in direct costs of 31.92% (P < 0.01), an increase in medicine costs of approximately 142% (P < 0.01), and a reduction in hospital costs of 68.15% (P > 0.05). There was no significant increase in total costs (P = 0.25), while 31.92% increase in direct costs (P < 0.01), and 35.62% decrease in indirect costs (P < 0.01) after conversion to PP1M. Compared with before administration of PP1M, patients with ≥ 1 inpatient stay in 1 year Pre-PP1M treatment with OAPs (n = 32) had a 20.16% decrease in direct costs (P < 0.01), a 144% increase in medicine costs (P < 0.01), and a significant 72.02% decrease in hospital costs (P < 0.01). The observed reduction in the number of hospitalizations (t = 2.56, P ≤ 0.01) and inpatient stays (t = 1.73, P < 0.05) and after transition to PP1M resulted in a reduction in hospitalization costs (P < 0.01).Switching from OAPs to PP1M decreased the household workforce burden without increasing clinical healthcare costs. Direct costs were significantly reduced in patients with ≥ 1 inpatient stay in 1 year pre-PP1M treatment with OAPs after the switch, which decreased by improving adherence to therapy and reducing the number and length of hospital stays, suggesting that those patients may benefit after switching to PP1M.