Objectives: The objective of this study is to compare the Dinakara and Cotes equations in their ability to predict post hematopoietic stem cell transplant (HSCT) pulmonary complications and mortality. Hypothesis We hypothesize the pre-transplant diffusing capacity adjusted for hemoglobin (DLCOHgb) by the Cotes equation in pediatric patients undergoing HSCT will predict morbidity and mortality more accurately than the Dinakara equation. Study-Design: Data was collected retrospectively from chart review of patients who underwent their first HSCT at Riley Hospital for Children using a database maintained by the Pediatric Stem Cell Transplant Program. Patient-Subject Selection: Patients who performed pre-transplant diffusing capacity for carbon monoxide (DLCO) that met ATS criteria, and a hemoglobin recorded within 7 days of their pulmonary function testing were included. Methodology: Paired t-tests and ANOVA models were used to define any differences between the two equations at baseline and when stratifying by hemoglobin level. Logistic regression models were used to determine associations between the Dinakara and Cotes equation with mortality at one- and three-years post-transplant. Results: 90 patients underwent HSCT during the study period, and 69 patients met inclusion criteria. Odds ratios for mortality using DLCO corrected for the Dinakara (1.08 SD 0.98-1.19) and Cotes (1.09 SD 0.97-1.22) were similar (p-value > 0.05). Neither Dinakara or Cotes corrective equation was superior at predicting pulmonary complications. (p-values 0.1388 and 0.5246 respectively) Conclusions: The Dinakara and Cotes equations differed in their calculation of DLCOHgb at lower Hb levels, their ability to predict mortality and pulmonary complications after HSCT was not different.