Sarcopenia is widely believed to be linked to poorer outcomes in inpatient rehabilitation. This study aimed to assess the impact of sarcopenia on functional outcomes and dietary intake during hospitalization in adults undergoing convalescent rehabilitation. We conducted a retrospective cohort analysis at a single rehabilitation institution. The Asian Working Group Consensus Criteria for Sarcopenia was used to diagnose. The Functional Independence Measure (FIM) score was used at hospital discharge to measure the primary functional outcome. Energy and protein intakes during hospitalization were calculated as part of the nutritional assessment. There were 126 patients in the research (median age, 73 yr; 54% women). Stroke (n = 73; 53.4% sarcopenia) and musculoskeletal disorders (n = 53; 56.6% sarcopenia) were among the admission diagnoses. Multiple linear regression analysis revealed that the FIM total score at discharge was modestly associated with sarcopenia only in stroke patients (β = −0.1872, P = 0.09), as well as significantly and independently associated with protein intake during admission only in stroke patients (β = 0.3217, P < 0.05). In hospitalized stroke patients undergoing convalescent therapy, sarcopenia is related to lower functional results. Early identification of sarcopenia and treatment with rehabilitation nutrition should be implemented in this population