First-generation 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists (RAs) are currently the standard of care for prophylaxis against allo-HSCT-induced emesis. However, the efficacy of this combination in allo-HSCT recipients is not entirely satisfying. We sought to compare the efficacy of first-generation 5-HT3 RAs with that of second-generation 5-HT3 RAs in emesis prevention in allo-HSCT recipients. A total of 51 consecutive patients undergoing allo-HSCT for various hematological diseases in our institution were retrospectively reviewed. Patients who received daily first-generation 5-HT3 RAs, and 60-h palonosetron for emesis prophylaxis were stratified into the standard (n = 23) and palonosetron (n = 28) groups, respectively. Emesis severity and rescue therapy requirements in patients between these two groups were compared. Our results showed patients in standard and palonosetron groups had comparable severity of both acute and delayed emesis. However, 52.2?% of the patients in the standard group required rescue therapy, compared to only 21.4?% of the patients in the palonosetron group (p = 0.046). Subgroup analysis showed rescue therapy for acute emesis was required by 26.1?% of the patients in the standard group and by only 3.6?% of the patients in the palonosetron group (p = 0.037). In conclusion, palonosetron and first-generation 5-HT3 RAs were at least equally effective in emesis prophylaxis for allo-HSCT recipients. Patients receiving palonosetron, especially for acute emesis, required rescue therapy less frequently than those receiving first-generation 5-HT3 RAs. ? 2014 Springer-Verlag Berlin Heidelberg.