Introduction/Background: Patients are readmitted for various complications during the first year post allogeneic hematopoietic cell transplantation (alloHCT). Readmissions are associated with higher utilization of health care resources and cost, negatively impacting quality of life. While several studies have described risk factors for readmission in adult patients, limited data are available for the pediatric AlloHCT recipients. Understanding and addressing the modifiable risk factors that drive readmissions after alloHCT can potentially improve transplant outcomes and decrease healthcare utilization. Objectives: This study aimed to identify modifiable risk factors associated with hospital readmission among pediatric alloHCT recipients. Design/Methods: A single-center retrospective cohort study was conducted, encompassing children discharged from the hospital after their first alloHCT between June 1, 2008, and January 2021. The primary endpoint of the analysis was hospital readmission after initial hospitalization for alloHCT. We studied three different aspects of readmissions: 1) whether readmission occurred, 2) the quantity of post-alloHCT readmissions per patient, 3) timing of readmission (early <30 days vs. late ≥30 days from first hospital discharge). Logistic regression was employed to evaluate pre-transplant characteristics, sociodemographic factors, and transplant complications associated with readmission. Results: Of 216 patients who were discharged after alloHCT, 186 were readmitted within a year, with a median number of readmissions at 2 (ranging from 0 to 17). On multivariable analysis, significant risk factors associated with readmission were non-English speaking families, occurrence of acute graft-versus-host disease (aGVHD) prior to discharge, CD4 count <10/uL , blood urea nitrogen >20mg/dL at the time of discharge, and presence of an external central line at discharge. The impact of an institutional practice change in 2019 to remove external central lines prior to discharge was studied to determine if readmission rates changed; readmission rates were higher in 2008-2018, before the change, as compared to after the in change 2019-2021 (90% vs. 71%, respectively). The primary etiology of readmission in the earlier time period as compared to the later was identified to be due to bacteremia (25% vs. 3%, respectively). Conclusions: Most children are readmitted following discharge after alloHCT. Modifiable risk factors should be targeted in future research efforts to decrease re-hospitalization. Prospective multicenter studies are needed which could potentially improve the outcomes and quality of life of children.