Objective This study aimed to determine the clinical outcomes and risk factors affecting mortality in patients with COVID-19 following hematological malignancy (HM). Methods Patients diagnosed with HM and hospitalized for COVID-19 were included in this retrospective study. The age, demographic and clinical characteristics, prognosis and treatment of surviving and non-surviving patients were compared. Results A total of 49 patients were included in this study, 17 (34.6%) of whom died within 28 days of being diagnosed with COVID-19. Older age (p = 0.001), diabetes (p = 0.001), chronic obstructive pulmonary disease (p = 0.002), secondary infection (p < 0.001) and secondary bacterial infection (p = 0.005) were statistically significantly higher in non-survivors. The remission status of HM was higher in surviving patients (p < 0.001). In multivariate regression analysis, age (OR: 1.102, p = 0.035) and secondary infection (OR: 16.677, p = 0.024) were risk factors increasing mortality, the remission status of HM (OR: 0.093, p = 0.047) was a protective factor from mortality. Conclusion The older age, the remission status of HM and secondary infection due to COVID-19 were determined as prognostic factors predicting mortality in HM patients with following COVID-19.