Objective: This study investigates the effectiveness of the Loving-Kindness and Mindfulness Meditation (LKM) therapy in improving mood states of hematologic malignancy patients in a sterile isolation room. A randomized controlled trial was conducted, with the POMS2 Japanese version used to assess mood state improvement. Methods: The final number of participants in this study was nine (intervention group n=4, control group n=5). Patients in a sterile isolation room were provided with a tablet containing a video of the LKM. The intervention group watched the 20-minute video. POMS2 factor scores were measured before the intervention and again one and two weeks after the intervention. The data were analyzed using two-way analysis of variance (ANOVA) to compare the scores across time points. Results: No statistically significant differences were observed between the two groups for each factors; however, a trend of nonlinear change was observed in the Vigor-Apathy (VA) factor(p=0.054). Conclusion: In this pilot study, LKM did not show a significant effect on the mood state of patients, which is suggested to be due to the insufficient number of cases. It seems necessary to increase the number of subjects in future research.