Introduction: Multimorbidity, characterized by the coexistence of multiple chronic conditions, presents a significant challenge in the rehabilitation of stroke survivors. Understanding the impact of multimorbidity on functional outcomes is crucial for optimizing post-stroke care. This study aimed to investigate the association between multimorbidity and functional outcomes in stroke survivors undergoing rehabilitation. Materials and Methods: Descriptive statistics were employed to analyze data from 270 stroke survivors. Multimorbidity was assessed based on the count of chronic conditions, and its influence on functional outcomes was evaluated using the Barthel Index scores. The reported statistics included means, 95% confidence intervals, and standard deviations. Results: Among the stroke survivors, 95.2% had multimorbidity, with 54.4% falling into the group with fewer than four chronic conditions and 49.6% in the group with four or more conditions. The mean Barthel Index score for stroke survivors with greater than four comorbidities was 60.74 (SD ± 13.08), with a 95% confidence interval ranging from 58.51 to 62.98. In comparison, stroke survivors with fewer than four comorbidities had a mean Barthel Index score of 71.06 (SD ± 9.47), with a 95% confidence interval ranging from 69.45 to 72.67. Conclusions: The high prevalence of multimorbidity among stroke survivors underscores its potential negative impact on post-stroke rehabilitation outcomes. The findings suggest that stroke survivors with a greater number of comorbidities tend to have lower functional scores, indicating poorer rehabilitation outcomes.