Background <p>Geriatric rehabilitation reduces mortality and long-term care home (LTCH) admission. However, cognitive impairment is often perceived to be a barrier for successful rehabilitation. Our objective was to determine the impact of cognitive impairment on rehabilitation outcomes using a systematic review of inpatient geriatric rehabilitation.</p> Methods <p>We conducted a secondary analysis of a recent systematic review and meta-analysis of geriatric rehabilitation in the inpatient settings. We screened 29 randomized controlled trials (RCTs) included in the original systematic review for those that reported rehabilitation outcomes (e.g. mortality, LTCH admission) by cognitive status (high vs. low cognition as defined by score cutoff or dementia diagnosis). Results were analyzed by (i) a meta-analysis of outcomes in those with cognitive impairment and (ii) pooling the within study interaction by cognitive status.</p> Results <p>Of 29 RCTs, 8 RCTs (1134 patients) reported outcomes by cognitive status. For the subgroup of patients with cognitive impairment, the risk ratio (RR) of mortality at the longest follow up was 0.75 (95% confidence interval [CI] 0.39 to 1.45, I² = 61.0%) and the RR of LTCH admission was 0.89 (95% CI 0.62 to 1.28, I² = 0). There was no interaction between baseline cognitive status and mortality (pooled interaction of difference in logRR − 0.12, 95% CI -0.72 to 0.48) or LTCH admission (pooled interaction 0.17, 95% CI -0.34 to 0.68).</p> Conclusions <p>There is no interaction between baseline cognitive status and the outcomes in this systematic review, suggesting that baseline cognitive impairment does not alter the mortality and institutionalization benefits of geriatric rehabilitation.</p> Review registration <p>PROSPERO: CRD42022345078.</p>