Objectives The purpose of this study was to adapt and validate the revised version of the Prolonged Grief Scale (PG-13-R), developed in accordance with the diagnostic criteria for Prolonged Grief Disorder inserted in DSM-5-TR, into Korean. The study aimed to confirm the factor structure, validity, and reliability of the scale. Methods Through translation and back-translation processes, the Korean version of the Prolonged Grief Scale (K-PG13-R) was constructed. The study participants were adults aged 18 and above who had experienced bereavement, with a bereavement period ranging from 1 to 5 years. Exploratory factor analysis, reliability, and validity testing were conducted with a sample of 266 bereaved individuals, and confirmatory factor analysis was performed with a separate sample of 402 bereaved individuals. Results Through exploratory factor analysis, it was confirmed that the scale consists of a single factor. This is consistent with findings from the development of the PG-13-R scale using samples from the United States, the Netherlands, and the United Kingdom. As a result of conducting confirmatory factor analysis using a different sample, it was verified that the single-factor structure model extracted through exploratory factor analysis was appropriate. Additionally, the scale demonstrated high internal consistency, as well as high convergent and concurrent validity, confirming that its reliability and validity are at acceptable levels. Conclusions This study holds significance in adapting and validating the PG-13-R revised in accordance with the formal diagnostic criteria for Prolonged Grief Disorder in DSM-5-TR into Korean. It is anticipated that this scale will contribute to evaluating and providing timely treatment for bereaved individuals in need of therapy.