Background: Stroke rehabilitation in inpatient setting requires high intensity of manpower and resources. Early stratification of patients with stroke could facilitate early discharge plan and reduce avoidable length of stay (LOS) in hospital. Stratification of patients with stroke in clinical setting is usually based on functional scores which are quite time-consuming and require a special training to complete the full score. Objective: The objective of the study was to explore whether Modified Functional Ambulation Category (MFAC) can serve as a stratification tool of patients with stroke in inpatient rehabilitation. Methods: This was a retrospective, descriptive study of the demographic, functional outcomes of patients with stroke in an inpatient rehabilitation center. A total of 2,722 patients completed a stroke rehabilitation program from 2011 to 2015 were recruited. The patients were divided into seven groups according to their admission MFAC. The between-group difference in LOS, functional outcomes at admission and discharge including Modified Rivermead Mobility Index (MRMI) and Modified Barthel Index (MBI) as well as MRMI gain, MRMI efficiency, MBI gain, and MBI efficiency were analyzed. Results: Subjects with admission categories of MFAC 2 and 3 had a highly significant ([Formula: see text]) MRMI gain (6.2 and 6.6, respectively) and subjects with admission categories of MFAC 3 to 5 had highly significant ([Formula: see text]) MRMI efficiency (0.34, 0.40, and 0.39, respectively). The subjects with admission categories of MFAC 2 to 5 had a highly significant ([Formula: see text]) MBI gain (9.7, 10.2, 9.3, and 7.0, respectively) and the subjects with admission categories of MFAC 4 to 5 had a highly significant ([Formula: see text]) MBI efficiency (0.70 and 0.72, respectively). The subjects with admission categories of MFAC 1 and 2 had a highly significant ([Formula: see text]) LOS (27.7 and 26.6, respectively). MFAC profile was also established to represent the distribution of discharge MFAC of subjects according to their admission MFAC. The chance of subjects with admission categories of MFAC 1 and MFAC 2 progress to any kind of walker (MFAC [Formula: see text] 2) is 12.7% and 58.2%, respectively. The chance of subjects with admission MFAC 3, MFAC 4 and MFAC 5 progress to independent walker (MFAC [Formula: see text] 5) is 6.7%, 14.8%, and 50.3%, respectively. Both admission MFAC and admission MBI had strong correlations with discharge MFAC ([Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text], respectively), discharge MRMI ([Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text], respectively) and discharge MBI ([Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text], respectively). Conclusion: This study showed that patients on admission with moderate disability in term of MFAC had the greatest mobility gain and basic activities of daily living (ADL) gain from inpatient stroke rehabilitation. Admission MFAC could be a stratification tool of patients with stroke in inpatient rehabilitation.