Objectives To investigate the effects of Computerized Neuropsychologic Test (CNT) on cognitive function and daily life performance in subacute post-stroke patients with cognitive impairment. Methods Korean Mini-Mentals State Examination (K-MMSE), Korean version of Modified Barthel Index (K-MBI) were investigated in 125 subacute post-stroke patients with cognitive impairment. We analyzed K-MMSE and K-MBI which were conducted 63 patients who had received CNT and 62 patient who had not received CNT from baseline to 8 weeks follow-up. In the experimental group, initial K-MMSE and K-MBI were conducted 13.3 ± 6.8 weeks after the onset of stroke and their age was 63.4 ± 13.3. In the control group, initial K-MMSE and K-MBI were conducted 13.2 ± 7.7 weeks after the onset of stroke and their age was 65.1 ± 11.6. Results The 8 weeks follow-up total K-MMSE score and total K-MBI score of experimental group were significantly higher than control group ( P < 0.05). In K-MMSE subsection, orientation, judgement, recall, language & visual reconstruction were significantly higher in experimental group than control group ( P < 0.05). In K-MBI subsection, personal hygiene, bathing self, toilet, dressing, ambulation, chair/bed transfer were significantly higher in experimental group than control group ( P < 0.05). The change of total K-MMSE score of experimental group was significantly correlated with change of total K-MBI score ( P < 0.05), but control group was not ( P > 0.05). In K-MMSE subsection, change of orientation, registration, language and visual reconstruction were correlated with total K-MBI s core after CNT. Especially, the experimental group, total K-MBI score of the left hemisphere damage group was significantly higher than the right hemisphere damage group ( P < 0.05). Conclusions This study shows that CNT is effective on subacute post-stroke patients with cognitive impairment. Improvement of cognitive function can expect a positive outcome on daily life performance, in particular, it can be expected to improve the prognosis of patients with stroke, the left hemisphere lesions.