Objectives: This study aimed to describe objectively measured physical activity and sedentary behavior in geriatric rehabilitation patients receiving care in the home-based compared to the hospital-based setting. Design: Observational matched cohort. Setting and Participants: Home-based (patient's home) or hospital-based (ward) geriatric rehabilitation was delivered to inpatients within the REStORing health of acutely unwell adulTs (RESORT) observational, longitudinal cohort of the XXXX Q 2 (Victoria, Australia). Methods: Patients were asked to wear ActivPAL4 accelerometers for 1 week and were assessed by a comprehensive geriatric assessment at admission, discharge, and followed up after 3 months. Hospitalbased were matched to home-based patients for sex and baseline physical function [Short Physical Performance Battery (SPPB), activities (instrumental) of daily living, and Clinical Frailty Scale]. Differences in patient characteristics and physical activity (total, standing and walking durations, number of steps and sit-to stand transitions) and sedentary behavior (total, sitting and lying durations) were assessed. Results: A total of 159 patients were included: 18 home-based [mean age: 81.9 AE 8.6 years, 38.9% female, median (interquartile range [IQR]) SPPB: 7.0 (5.0-9.0)] and 141 hospital-based [mean age: 82.9 AE 7.8 years, 57.4% female, median (IQR) SPPB: 1.0 (0.0-4.0)] patients, of whom 18 were matched [mean age: 80.1 AE 7.4 years, 38.9% female, median (IQR) SPPB: 6.5 (4.8-10.0)]. Median physical activity measures were consistently higher in home-based compared to the total group of hospital-based patients. After matching, physical activity measures remained >2.4 times higher and were significantly different for all measures (total physical activity, standing and walking durations, and steps) except for sit-to-stand transitions. Sedentary behaviors were similar with home-based patients spending nonsignificantly more time sitting but significantly less time lying than hospital-based patients (matched and total).The authors declare no conflicts of interest.