Abstract: FMS-like tyrosine kinase 3 (FLT3) mutations occur in around 30% of patients in acute myeloid leukemia (AML), and are generally associated with unfavorable outcomes. Gilteritinib is a highly specific second-generation class I FLT3 inhibitor, which can efficiently and specifically bind to the kinase domain. It can inhibit FLT3 receptor signal transduction to inhibit the growth of AML cells, reduce cell proliferation and induce apoptosis. It has been demonstrated that single-agent gilteritinib therapy is superiority to salvage chemotherapy (SC) in relapsed or refractory (R/R) FLT3-mutated AML based on significantly longer overall survival (OS). To evaluate the clinical efficacy of combinatorial targeted therapeutic approaches, here we reported a case of refractory AML with FLT3-ITD mutation that was treated with gilteritinib combined with BCL2 inhibitor venetoclax regimen, and bone marrow aspiration performed after 2 cycles of the targeted therapy was compatible with complete remission (CR). During the whole treatment process, no serious adverse events were observed. However, the primary disease recurred 1 month after achieving CR state, and the NRAS mutation developed. The patient eventually died of severe infection and multiple organ failure. Despite this, it was demonstrated that that gilteritinib combined with venetoclax can be a safe and effective regimen in R/R AML with FLT3 mutations and activating RAS/MAPK pathway mutations may confer resistance to gilteritinib.