Background Hematopoietic stem cell transplantation (HSCT) is a critical treatment for various hematologic malignancies but can lead to complications, including ototoxicity. Aim/objectives This study aims to explore the relationship between patient-specific factors and ototoxicity in adult HSCT patients. Material and Methods We conducted a retrospective analysis of 129 adult patients who underwent HSCT between 2003 and 2020. Age, gender, transplant indications, conditioning regimens, and pre- and post-transplant audiometry thresholds data were collected from patient files. A hearing loss of 10 decibels or more at two consecutive frequencies or a hearing loss of 20 decibels or more at a single frequency was considered as significant hearing loss (SHL). Statistical analyses were performed to describe factors associated with SHL. Results SHL occurred in 16.3% of patients. Older age was significantly associated with an increased risk of SHL (p = .035). Poorer pretransplant hearing thresholds at 4000 Hz and 6000 Hz were also significant predictors of SHL (p = .039 and p = .014, respectively). There was no significant relationship between the donor type of HSCT (autologous vs. allogeneic) and ototoxicity (p = .45), and between conditioning regimens and ototoxicity (p = .860). Conclusions Age and pre-existing hearing levels are significant predictors of ototoxicity post-HSCT. Careful management and monitoring are essential to prevent and address hearing loss in HSCT patients to improve hearing-related quality of life.