Purpose: Patients with hematologic malignancy (HM) typically have a high mortality rate when their condition deteriorates. The chronic progressive course of the disease makes it difficult to assess the effect of intervention on acute events. We investigated the effectiveness of a rapid response team (RRT) on in-hospital mortality in patients with HM. Methods: We retrospectively analyzed the data of patients with HM who admitted to the medical intensive care unit between 2006 and 2015. Clinical outcomes before and after RRT implementation were evaluated. Results: A total of 228 patients in the pre-RRT period and 781 patients in the post-RRT period were included. The overall in-hospital mortality was 55.4%. Patients in the post-RRT period had improved survival; however, they required more vasopressor therapy, continuous renal replacement therapy, and extracorporeal membrane oxygenation. Multivariate analysis revealed that in-hospital mortality was associated with RRT activation (hazard ratio [HR], 0.634; 95% confidence interval [CI], 0.498-0.807; p < .001), neurological disease (HR, 2.007; 95% CI, 1.439-2.800; p < .001), sequential organ failure assessment score (HR, 1.085; 95% CI, 1.057-1.112; p < .001), need for continuous renal replacement therapy (HR, 1.608; 95% CI, 1.206-1.895; p< .001), mechanical ventilation (HR, 1.512; 95% CI, 1.206-1.895; p< .001), vasopressor (HR, 1.598; 95% CI, 1.105-2.311; p = .013), and extracorporeal membrane oxygenation (HR, 1.728; 95% CI, 1.105-2.311; p = .030). Conclusion: RRT activation may be associated with improved survival in patients with HM.