This study aims to determine the effectiveness of paliperidone extended release (ER) on cognitive function in patients with schizophrenia in comparison with risperidone. This was a 12-week, randomized, open-label study on schizophrenia patients who were receiving risperidone. The patients were randomized to a risperidone-continuation group or a paliperidone-switch group. The primary outcome measure was neurocognitive function, which was measured using a computerized battery. Secondary efficacy measures included the Positive and Negative Syndrome Scale, Social and Occupational Functioning Scale, and Calgary Depression Scale for Schizophrenia. In total, 58 patients participated in this trial. Improvements in recall after an interference phase in the verbal learning test were significantly greater in the paliperidone-switch than in the risperidone-continuation group. No significant differences in changes were observed in the other six neurocognitive domains measured. Improvements in the Social and Occupational Functioning Scale were significantly greater in the paliperidone ER-switch group than in the risperidone-continuation group. In other efficacy outcome measures, no significant differences were observed between the two drugs. Paliperidone ER had a side-effect profile similar to that of risperidone, including metabolic problems and prolactin-related adverse events. In conclusion, switching from risperidone to paliperidone ER may lead to additional cognitive and social functional improvements.