Abstract Circulating tumor cells (CTCs) are tumor cells that have disseminated from primary and metastatic sites, and circulate in the bloodstream. Advanced immunological and molecular-based methods can be used to detect and analyze the cells with the characteristics of tumor cells, and can be detected and analyzed in the blood of cancer patients. The most commonly used methods in lung cancer combine the processes of immunomagnetic enrichment and immunocytochemical detection, morphology-based enrichment coupled with reverse transcriptase polymerase chain reaction (RT-PCR), and RT-PCR alone. CTC analysis is considered a liquid biopsy approach for early diagnosis, risk stratification, evaluation of curative efficacy, and early detection of lung cancer relapse. In this review, we dis...