We retrospectively analyzed the clinical outcomes of patients with pulmonary impairment before undergoing allogeneic hematopoietic stem cell transplantation (HSCT) for the first time. Among 297 evaluable patients who underwent their first HSCT, 23 had restrictive, obstructive or mixed ventilatory impairment (n = 9, 13 and 1, respectively). Males predominated among the patients with pulmonary impairment (p = 0.037) and received a reduced intensity conditioning (RIC) regimen more frequently, although the difference did not reach statistical significance (p = 0.05). Among 23 patients with pulmonary impairment, 9 underwent post-transplant pulmonary function tests and obstructive ventilatory impairment progressed only in 2 patients, both of whom developed bronchiolitis obliterans. Kaplan-Meier estimates of 3-year overall (OS) among patients with and without pulmonary impairment were 57% and 47%, respectively, and those of relapse-free survival (RFS) were 70%, and 68%, respectively, with no significant differences between the groups (OS, p = 0.235; RFS, p = 0.287). The rates of non-relapse mortality also did not significantly differ (p = 0.835). Our results suggest that allogeneic HSCT is safe for patients with pulmonary impairment. The lower frequency of fatal pulmonary complications after HSCT and the RIC regimen might contribute to favorable survival rates.