Carcinoembryonic antigen (CEA) is a prognostic marker for early-stage non-small cell lung cancer (NSCLC), and cryoablation is a new therapeutic alternative for lung cancer. We determined whether cryoablation-induced changes in serum CEA levels correlated with tumor type (adenocarcinoma or squamous carcinoma) and treatment type (comprehensive therapy [cryoablation of all intra- and extrapulmonary tumors] or palliative therapy [cryoablation of only extrapulmonary tumors]) in patients with metastatic NSCLC, and assessed whether pre-treatment CEA levels predicted overall survival (OS). We retrospectively reviewed the clinical data of 88 patients with metastatic NSCLC who underwent comprehensive (62 patients) or palliative (26 patients) therapy.