Purpose: The purpose of this study was to develop a new version of Spirituality Assessment Scale (N-SAS) and verify its reliability and validity. Methods: The total of 59 preliminary items for the N-SAS were selected through a literature review, two rounds of experts’ content validation, cognitive interviews, and pre-tests. Verification of its reliability and validity was divided into two phases. In Phase 1, questionnaires were collected from 219 adults. Reliability was tested using Cronbach's alpha, validity with item analysis, and exploratory factor analysis. In Phase 2, questionnaires developed based on the results of Phase I were collected from 225 adults. Reliability was tested using Cronbach's alpha, validity with confirmatory factor analysis, and criterion validity. Results: The final version of the N-SAS comprised two dimensions (vertical and horizontal), four domains (relationship with God; meaning of life and self-integration; self-transcendence; and relationship with others, neighborhoods, and nature), and 44 items were identified. Total Cronbach's alpha was .97; those of each subscale ranged from .79 to .98. N-SAS scores were positively correlated with the scores of Howded's Spiritual Assessment Scale (r=.81, p <.001). Conclusion: Findings suggest that the N-SAS can be used to measure spirituality in adults. The use of N-SAS is expected to facilitate perceiving patient's spiritual needs and providing spiritual care.