Introduction: During the subacute phase of a stroke, multidisciplinary rehabilitation aims to restore or compensate for functional limitations. The purpose of this study was to determine whether the intensity of rehabilitation had an effect on functional improvement. Method: Patients hospitalized in the follow-up care and rehabilitation (SSR) unit for stroke (ICD-10 codes I60 to I64, excluding I63.6) during the first eight months of 2016 were selected from the PMSI-SSR database. The daily duration of rehabilitation and its functional impact were obtained from the PMSI-SSR database. Three multivariate analyses were performed to examine factors associated with a better prognosis (presented as odds ratios [OR] with 95% confidence intervals [95% CI]). Results: The study population consisted of 12,122 patients with a median age of 76 years. The median length of stay (MLS) was 56 days, and the median daily rehabilitation duration was 90 minutes. In the multivariate analysis, a daily rehabilitation duration of 90 to 120 minutes (compared with less than 30 minutes) was associated with a higher probability of increased independence, low dependency, and discharge home following hospitalization (ORs of 1.87 [1.56–2.22], 1.88 [1.51–2.33], and 2.02 [1.65–2.46], respectively). Conclusion: This study demonstrated the likely functional impact of rehabilitation intensity during the subacute phase of a stroke. The scope of this retrospective study remains limited by the fact that patients most likely to improve may have benefited from more intensive rehabilitation.