ObjectivesThis study aimed to validate the Japanese version of the Survey of Perceived Organizational Support (SPOS-J) for the Japanese workforce by examining its reliability, factorial, construct, and test-retest validity.MethodsWe conducted an online baseline survey with 6,220 employed Japanese individuals, followed by a follow-up survey two weeks later to examine the test-retest reliability of the SPOS-J. The SPOS-J was translated in accordance with the ISPOR Task Force Guidelines. Both confirmatory and exploratory factor analyses were utilized to examine factorial validity. Construct validity was assessed using Pearson’s correlation analysis, while internal consistency was determined through the calculation of Cronbach’s alpha values. Additionally, test-retest reliability was evaluated with Cohen’s weighted kappa and intraclass correlation coefficients.ResultsThe SPOS-J demonstrated a better fit for a two-factor structure, comprising two subscales - SPOS-J (supported) and SPOS-J (unsupported) – compared to the one-factor structure of the original version. It exhibited high internal consistency, with Cronbach’s alpha coefficients of .93 for the overall SPOS-J, .97 for the SPOS-J (supported), and .95 for the SPOS-J (unsupported). Test-retest reliability was found to be good for the overall SPOS-J (.62) and moderate for its subscales, with Cohen’s weighted kappa values of .54 for SPOS-J (supported) and .42 for SPOS-J (unsupported). The construct validity was confirmed with significant correlations between the SPOS-J, its antecedents, and outcomes.ConclusionsThe SPOS-J is a reliable and valid measure for assessing perceived organizational support among Japanese workers.