Background Cluster of differentiation 163 (CD163) is a biomarker correlated with several normal and pathological states. Aim This work was carried out to evaluate the expression of CD163 in patients with acute leukemia. Patients and methods The study was carried out on 50 participants divided into three groups: 10 apparently normal healthy individuals, 30 patients with acute myeloid leukemia (AML), and 10 patients with acute lymphoid leukemia. All participants were subjected to a thorough history and clinical examination. Becton–Dickinson Calibur FACScan color multiparameter flow cytometry was used for the detection of CD163 expression in patients with acute leukemia. Results There was a significant difference in CD163 expression between AML and acute lymphoid leukemia (F=7.83) (P=0.001). CD163 expression was not observed in patients with acute lymphoblastic leukemia. However, it was expressed in 14 patients with acute myeloblastic leukemia. Five patients were diagnosed as M4, and all of them (100%) showed positive expression of CD163. Eight patients were diagnosed as M5, and all of them (100%) showed positive expression of CD163. However, CD163 was expressed in only one case among 17 patients with AML subtypes other than M4/M5. There was a significant difference between monocytic and nonmonocytic leukemic patients regarding CD163 expression (P<0.001). There was a strong correlation between CD163 and other markers predominantly found in monocytic leukemia such as CD14 (r=0.8) (P<0.001), CD15 (r=6.43) (P<0.001), and CD64 (r=0.82) (P<0.001). Conclusion CD163 was exclusively expressed on the monocytic and myelomonocytic leukemia, so it can be used for the diagnosis of the monocytic type of AML. Although it cannot be used as a prognostic marker, it could be a novel immunotherapeutic intervention for acute monocytic and myelomonocytic leukemia.