Factors predicting allogeneic hematopoietic cell transplantation (HCT) outcomes in myelofibrosis in the early post-HCT period have not been defined thus far. We attempt to study such factors that can help identify patients at a higher risk of relapse or death. This retrospective study included 79 patients who underwent first HCT for myelofibrosis at three centers between 2005 and 2016. Univariate analysis showed that red blood cell (RBC) transfusion dependence (HR 9.02, 95% CI 4.0-20.35), platelet transfusion dependence (HR 8.17, 95%CI 3.83-17.37), 100% donor chimerism in CD33 + cells (HR 0.21, 95%CI 0.07-0.62), unfavorable molecular status (HR 4.41, 95%CI 1.87-10.39), normal spleen size (HR 0.42, 95%CI 0.19-0.94), grade ≥ 2 bone marrow fibrosis (vs. grade ≤ 1; HR 2.7, 95%CI 1.1-6.93) and poor graft function (HR 2.6, 95%CI 1.22-5.53) at day +100 were statistically significantly associated with relapse-free survival (RFS). RBC transfusion dependence and unfavorable molecular status were also statistically significant in the multivariate analysis. Patients in whom both of these factors were present had a significantly worse RFS when compared to those with one or none. While limited by a small sample size, we demonstrate the significance of transfusion dependence and molecular status at day +100 in predicting outcomes.