Objective To investigate the expression of miR-23a in peripheral blood and analyze its correlation with the clinic-pathological features of patients with lung cancer. Methods The level of miR-23a in peripheral blood of 63 patients with lung cancer and 60 healthy persons was detected using real-time reverse transcription-polymerase chain reaction (RT-PCR), The correlation between miR-23a level and the clinic-pathological features was analyzed. Results The expression level of miR-23a in peripheral blood of patients with lung cancer was significantly higher than that in the healthy persons (P < 0.01).The level of miR-23a was associated with TNM stage (P < 0.05), Lymphatic metastasis (P < 0.01) and the number of chemotherapy (P <0.01). Conclusion The miR-23a level in peripheral blood might be a molecular marker for the diagnosis and prognosis of patients with lung cancer.