Purpose: Designated multidisciplinary rehabilitation units have been shown to provide several benefits for the frail older population. The aim of this research was to evaluate changes in strength, mobility, balance, endurance, frailty and quality of life (QoL) following a 6-week multidisciplinary inpatient rehabilitation programme. Method: This was a prospective, observational study performed in a post-acute multidisciplinary geriatric inpatient rehabilitation service. A consecutive sample of heterogenous frail older adults (n = 32) participated. Subjects were assessed on admission to the rehabilitation service (T1) and following 6 weeks of rehabilitation (T2). A range of outcome measures were used to assess function and QoL: Berg Balance Scale (BBS), Timed Up and Go (TUG), 6-Minute Walk Test (6MWT), Barthel Index (BI), EuroQol-Visual Analogue Scale (EQ-VAS), Clinical Frailty Scale (CFS), lower limb and grip dynamometry. Results: The majority were female (n = 25), the mean age was 82.9 years (SD 6.35). The median length of stay was 49 days. Patients improved significantly between T1 and T2 assessments in the BBS (p ≤ 0.0001); TUG (p ≤ 0.0001); 6MWT (p ≤ 0.0001); BI (p ≤ 0.0001); EQ-VAS (p = 0.002); CFS (p ≤ 0.0001); and in some aspects of grip and lower limb strength. Conclusion: This study has demonstrated that positive outcomes occurred in a range of measures in an older, frail inpatient rehabilitation population.Implications for RehabilitationElderly inpatients undergoing rehabilitation programmes improve across a range of measures looking at impairment, activity, participation and quality of life.However, gains were modest and patients did not attain their baseline level of performance after a 6-week programme of inpatient rehabilitation.Using outcome measures in clinical rehabilitation practice can facilitate comparison between units and can form the basis for future research in this population.