Objectives: The evidence supports early and intensive mobilization and physical activity for hospitalized patients following a hip fracture. Since bedrest and inactivity during acute care are potentially fatal, we need updated knowledge of levels of physical activity in a diverse clinical population. Therefore, the objective was to determine levels of physical activity among a broad representation of patients hospitalized following hip fracture, and secondly to explore the association with 30-day post-discharge readmission, and mortality. Design: Prospective cohort study Setting: Data were collected at two university hospitals in the Capital Region of Denmark from March to June 2023. Participants: Patients hospitalized following hip fracture. Main outcome measures: 24-hr upright time (time standing and walking) was measured from inclusion (post-operative day (POD) 1-3) to discharge using a thigh-worn accelerometer. Readmission and mortality were verified by electronic patient records. Results: 101 patients (62 women) with a mean (SD) age of 79.9 (8.4) years were included. The median (IQR) 24-hr upright time on POD2-6 ranged from 15 (6.9:31.0) to a maximum of 34 (16:67) mins. Patients with cognitive impairment had less upright time than patients without. Post-surgery length of stay was a median of 7 (5:8) days. 25% of the patients were readmitted or had emergency ward referrals and 3% died within 30 days of discharge (no clear association with upright time). Conclusions: Physical activity seems extremely low among a broad representation of patients within the first week following a hip fracture but was not found to influence readmissions. Considering the strong evidence supporting physical activity during acute hospitalization, the low activity level in these patients calls for action. Clinicaltrials.gov-identifier:NCT05756517