Background: The Coronavirus Disease 2019 (COVID-19) has caused over 25 million infections in the US with over 0.4 million deaths. Hematogenic stem cell transplant (HCT) or cellular therapy (CT) recipients have a high risk of mortality with COVID-19 due to profound immune dysregulation. We aimed to assess the outcomes with COVID-19 in HCT/CT recipients. Methods: A single-center prospective study was conducted, including all (n=40) adult HCT/CT patients who were diagnosed with COVID-19 at the University of Kansas from Apr 2020 to Jan 2021. Baseline and disease-related characteristics were ascertained from medical records. Data were analyzed using SPSS version 21 (SPSS Inc, Chicago, IL). Bivariate analyses, using chi-square and t-test, and logistic regression analyses were conducted. Results: The study included 40 COVID-19 patients (72.5% Oct 2020-Jan 2021), including allogeneic HCT (n=25), autologous HCT (n=13) and CAR-T CT (n=2) with median time since HCT/CT of 12.4 (1-201.9), 37.2 (0.4-118.7), and 3.8 (2.8-4.8) months. Seventy percent were Caucasians and 17.5 were Hispanics. Primary hematologic malignancy was myeloid (37.5%), lymphoid (35%) or plasma cell disorder (27.5%). Myeloablative conditioning was performed in 65% of patients. Donors were autologous (37.5%), matched sibling (17.5%), matched unrelated (22.5%) and haploidentical (22.5%). COVID-19 was mild (42.5%), moderate (42.5%) or severe (15%). Clinical findings included pneumonia (62.5%), hypoxia (25%) and ICU admission (17.5%) while therapies included remdesivir (47.5%), convalescent plasma (40%), dexamethasone (25%) and monoclonal antibodies (17.5%). Concurrent cancer treatment, other infections and active GVHD were reported in 25% (all myeloma), 20% and 32.5% of patients. After a median follow-up of 74 days (7-269), the mortality rate was 12.5% in all patients and 20% in allo-HCT patients. Significant predictors of COVID-19 severity included allogeneic HCT, concurrent immune suppression and elevated inflammatory markers. (Table). Conclusions: Hematopoietic stem cell transplant recipients have an increased risk of mortality with COVID-19. Our findings confirm the need for vaccination prioritization, close monitoring, and aggressive treatment in HCT/CT patients.