There is an urgent need to achieve more efficient and rapid donor coordination process in the Japan Marrow Donor Program (JMDP). We conducted a questionnaire survey to evaluate the relationship between stem cell donation and the psychosocial background of unrelated donors registered to JMDP. Unrelated donors who donated stem cells or who terminated coordination of JMDP for reasons not including health conditions or patient-related factors were enrolled in April and May 2017. Of 870 donors (non-donation group, 738 donors; donation group, 132 donors) who were mailed questionnaires, 385 donors (non-donation, 315; donation, 70) responded. Multivariate logistic regression showed that high cooperativity (scored on a five-point scale), low anxiety regarding donation, and low difficulty controlling work/family issues were significantly associated with successful donation. Donors who had donated blood frequently (>10 times) showed an odds ratio of 2.5 for stem cell donation, by univariate analysis. In the non-donation group, the reasons for not donating were “Donation may affect my work/I could not arrange my work schedule” in 43% of donors, “My family disagreed” in 21%, “May affect family life” in 15%, and “concern/fear about the risk of donation” in 11%. Using factors we found to be associated with donation (cooperativity, anxiety, and control of work/family issues), a large-scale survey is warranted to put up concrete measures.