Background: Patients with Parkinson disease (PD) undergoing total knee arthroplasty (TKA) can present with a unique subset of challenges during their hospital stay. The literature is limited to single-center studies with a small number of patients. This study was aimed to analyze the inpatient complications, length of stay (LOS), and cost of care (COC) associated after TKA with PD over 4 years (2016 to 2019). Methods: In this retrospective cohort study, we used National Inpatient Sample (NIS) database data from 2016 to 2019 and compared in-hospital complications, LOS, and COC among patients undergoing TKA with and without PD. Results: The National Inpatient Sample database is used to identify 558,371 patients (555,289 without PD and 3,082 with PD) who underwent TKA. After propensity-matching, there was an increased incidence of blood loss anemia (PD group 22.3%, control group 13.5%, P # 0.01), periprosthetic dislocations (1.5% in PD group, 0.4% in control group, P , 0.001), and periprosthetic mechanical complications including but not limited to periprosthetic fractures, knee dislocations, patellar maltracking, and subluxations (1.1% in PD group, 0.6% in control group, P = 0.024) in the PD group. The other inhospital complications including mortality, acute renal failure, myocardial infarction, pneumonia, pulmonary embolism, deep vein thrombosis, periprosthetic fracture, and wound dehiscence showed no notable differences. The average total incurred charges for the PD group were higher, with a mean of $67,581.58 (SD $44,554.64), than that in the control group, with a mean of $64,795.51 (SD $45,841.25) (P , 0.001). The average LOS was higher in the PD group with a mean of 2.7 days (SD = 1.93) compared with the control group (mean = 2.3, SD = 1.73 days, P , 0.001).