This clinical trial investigates the facilitating effects of combining tDCS with EEG-based motor imagery Brain-Computer Interface (MI-BCI) robotic feedback compared to sham-tDCS for upper limb stroke rehabilitation. 32 hemiparetic stroke patients were recruited and screened for their ability to use EEG-based MI-BCI. Subsequently, 17 of these patients who passed screening and gave further consent were randomized to receive 20 minutes of tDCS or sham-tDCS prior to 10 sessions of 1-hour MI-BCI with robotic feedback for 2 weeks. The offline and online accuracies of detecting motor imagery from idle condition for the calibration session and the evaluation part of the 10 rehabiltiation sessions were respectively assessed. The results showed that there were no significant difference in the accuracies of the calibration session from both groups, but the online accuracies of the evaluation part of 10 rehabilitation sessions of the tDCS group were significantly higher than the sham-tDCS group. Hence the results suggest towards tDCS effect in modulating motor imagery in stroke.