['Despite the fact that proton pump inhibitor (PPI) use is a risk factor for infections in heterogeneous groups of patients, there are only a limited data related to PPI use and febrile neutropenic episodes (FNEs) in hematopoietic stem cell transplantation (HSCT) patients.', 'In a 7-year period, we retrospectively reviewed 145 HSCT data to identify a risk factor for PPI use for febrile neutropenia. The follow-up process of 125 (86.2%) of the HSCTs was complicated with FNEs.', 'A multivariate analysis indicated that PPI use was not significantly associated with FNEs (Odds ratio [OR]: 0.46; 95% Confidence Interval [CI] 0.12-2.16; p = 0.24) or bacterial culture positivity (OR: 1.37; 95% CI 0.45-4.18; p = 0.58).'] Does use of proton pump inhibitors in hematopoietic stem cell transplantation increase the frequency of febrile neutropenia?