Purpose: This study aimed to develop a digital multimedia-based educational intervention for hematopoietic stem cell (HSC) donors and to evaluate its effects on anxiety, knowledge, attitudes toward hematopoietic stem cell donation, and educational satisfaction. Methods: This quasi-experimental study employed a nonequivalent control group non-synchronized pretest-posttest design. Participants were 60 HSC donors admitted to a general hospital in Seoul, Republic of Korea, between April and December 2024. The participants were assigned to an experimental group (n=30) and a control group (n=30). The experimental group received a digital multimediabased educational intervention in addition to the usual education using a standardized handout, whereas the control group received the usual education only. The intervention was provided in three sessions: on the day of admission (20 minutes), on the day of stem cell collection (10 minutes), and on the day of discharge (10 minutes). Data were collected at admission and discharge using structured questionnaires. Anxiety was analyzed using generalized estimating equations (GEE), knowledge and attitudes using mixed ANOVA, and educational satisfaction using an independent t-test. Results: The experimental group showed significantly lower anxiety (p=.048) and higher knowledge levels (p=.005) than the control group. No significant differences were found between the groups in attitudes toward donation or educational satisfaction. Conclusion The digital multimedia-based educational intervention was effective in reducing anxiety and improving knowledge among HSC donors. This intervention may enhance donors’ understanding of the donation process and support a more positive donation experience. Further multicenter studies with larger samples and longitudinal follow-up measurements are needed to verify the long-term effects and generalizability of the intervention.