Lung cancer is the most commonly diagnosed type of cancer worldwide. About 90 % lung cancer patients died within 5 years after diagnosis. It is reasonable to assume that early detection of lung cancer could reduce mortality. MicroRNAs (miRNAs) are a class of small noncoding, single-stranded RNAs that regulate gene expression by affecting the stability or the translation efficiency of target messenger RNAs. Altered expressions of miRNAs were associated with the development, invasion, metastasis and prognosis of cancer. Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Here, we describe a blood test based on detection of serum miRNAs that distinguish early NSCLC patients from healthy volunteers. Three miRNAs, miR-17, 21 and 192 expression levels were significantly higher in the stage I NSCLC patients than the healthy volunteer groups. This suggests that miR-17, 21 and 192 could be considered as biomarkers for diagnosis of early-stage NSCLC.