BACKGROUND: Robot-assisted therapy (RT) has become a promising stroke rehabilitation intervention. OBJECTIVE: To examine the effects of short-term upper limb RT on the rehabilitation of sub-acute stroke patients. METHODS: Subjects were randomly assigned to the RT group (n= 23) or conventional rehabilitation (CR) group (n= 22). All subjects received conventional rehabilitation therapy for 30 minutes twice a day, for 2 weeks. In addition, the RT group received RT for 30 minutes twice a day, for 2 weeks. The outcomes before treatment (T0) and at 2 weeks (T1) and 1 month follow-up (T2) were evaluated in the patients using the upper limb motor function test of the Fugl-Meyer assessment (FMA) the Motricity Index (MI), the Modified Ashworth Scale (MAS), the Functional Independence Measure (FIM), and the Barthel Index (BI). RESULTS: There were significant improvements in motor function scales (P< 0.001 for FMA and MI) and activities of daily living (P< 0.001 for FIM and BI) but without muscle tone (MAS, P> 0.05) in the RT and CR groups. Compared to the CR group, the RT group showed improvements in motor function and activities of daily living (P< 0.05 for FMA, MI, FIM, BI) at T1 and T2. There was no significant difference between the two groups in muscle tone (MAS, P> 0.05). CONCLUSIONS: RT may be a useful tool for sub-acute stroke patients’ rehabilitation.