Circulating tumor cels (CTCs) are tumor cels that enter the blood circulation after detaching from the primary tumor and can migrate to reach distant organs, where they can give rise to aggressive metastasis. Clinical studies have revealed that the presence of CTCs in peripheral blood is correlated with disease progression in lung cancer. However, as CTCs are rare cancer cels released from tumors into the bloodstream, both enrichment and sensitive detection methods are technicaly chalenging. In order to best understand how CTCs are currently being deployed, this review mainly focuses on the diferent detection methods for CTCs. Furthermore, we wil describe the clinical impact of circulating tumor cels in lung cancer and discuss their potential use as biomarker to guide the prognosis.