The aim of this study is to search critical renin-angiotensin system (RAS) elements in myeloid leukemic cell lines. Human acute myeloid leukemia (AML) cell lines, KG-1 and HL-60, were cultured. We searched for the gene expression of the major RAS components in KG-1 and HL-60 cell lines by quantitative real-time polymerase chain reaction analysis (qRT-PCR). Angiotensin-converting enzyme I (ACE I) and ACE II mRNA expressions were detected in KG-1 AML cell line. Relative expression of ACE I was higher than ACE II expression in this myeloid leukemic cells. Likewise, RENIN, angiotensinogen (ANGTS), and ACE I mRNA expressions were detected in HL-60 promyelocytic cell line. Relative RENIN expression was the highest, whereas ACE I expression was the lowest in HL-60 neoplastic myeloid cells. These findings indicate that there is a biologically active local RAS in the hematopoietic system in normal and pathological states.