OBJECTIVE: To develop the Korean version of the Kessler Foundation Neglect Assessment Process (KF-NAP), which enables a more functional assessment of unilateral spatial neglect, by first translating it into Korean and then statistically standardizing it. METHODS: Two rehabilitation specialists translated the KF-NAP into Korean. The entire process of administering the Korean KF-NAP to 30 patients with brain disease was video-recorded. Five occupational therapists from 4 university hospitals nationwide evaluated the 30 video-recorded examination cases. We analyzed inter- and intra-reliabilities of the Korean KF-NAP using the intraclass coefficient and Pearson correlation coefficient. Internal consistency reliability of the assessment categories was also examined using Cronbach's alpha coefficient. RESULTS: For the construct validation study, the Korean KF-NAP was strongly correlated with the Albert's test and letter cancellation test (r ≥ 0.8; p < 0.05). The intraclass correlation coefficients for the first and second assessments of the Korean KF-NAP were 0.973 and 0.982, respectively, showing high reliability (p < 0.05). The intra-rater reliabilities exceeded 0.9 (p < 0.05), and Cronbach's alpha coefficient exceeded 0.8, showing internal consistency reliability. CONCLUSION: The Korean KF-NAP is a reliable and valid instrument for assessing hemispatial neglect symptoms in patients with brain diseases.