In recent years, many researches have shown that OCT4 is overexpressed in both germ cell tumors and somatic cancers. Meanwhile, OCT4 has relationship with poor prognosis in a lot of solid tumors, such as hepatocellular carcinoma, gastric cancer, and esophageal cancer. In our study, we investigated the expression status of OCT4 and its clinical significance in patients with acute myeloid leukemia (AML) using real-time quantitative PCR. The receiver operating characteristic (ROC) curve reveals that the level of OCT4 expression could be available for a potential diagnostic biomarker for differentiating AML from controls with an area under the ROC curve (AUC) of 0.915 (95 % confidence interval (CI) 0.837-0.992; P < 0.001). At the cutoff value of 0.56, the sensitivity and the specificity are 75.9 and 81.2 %, respectively. The amount of white blood cell (WBC) of patients with high OCT4 expression is higher than that of patients with low OCT4 expression (18.2 × 10(9) versus 2.7 × 10(9) L(-1), P = 0.001). Among those patients who are less than 70 years old, patients with OCT4 high expression have significantly shorter overall survival (OS) than those without OCT4 high expression (P = 0.048). These findings suggest that OCT4 high expression is a common event and may have an adverse impact on prognosis in AML.