BACKGROUND lncRNA-ATB plays an oncogenic role in various types of malignancies, but its involvement in papillary thyroid carcinoma (PTC) cells, which is a main type of thyroid cancer, is unknown. MATERIAL AND METHODS A total of 76 patients with PTC and 28 people with normal physiological conditions were included in this study. Tumor tissues and adjacent healthy tissues were collected from PTC patients and blood was extracted from both patients and healthy controls. Expression of lncRNA-ATB in those tissues was detected by qRT-PCR. All patients were followed up for 5 years and diagnostic and prognostic values of serum lncRNA-ATB for PTC were investigated by ROC curve analysis and survival curve analysis, respectively. lncRNA-ATB overexpression PTC cell lines were established and effects of lncRNA-ATB overexpression on cell migration and invasion were investigated by Transwell cell migration and invasion assay, respectively. Effects of lncRNA-ATB overexpression on TGF-β1 expression were investigated by Western blot. RESULTS lncRNA-ATB expression level was higher in tumor tissues than in adjacent healthy tissues in most PTC patients. Serum level of lncRNA-ATB was higher in cancer patients than in healthy control. Serum lncRNA-ATB can be used to accurately predict PTC and its prognosis. lncRNA-ATB overexpression promoted tumor cell migration and invasion, lncRNA-ATB overexpression showed no significant effects on TGF-β1 expression, and TGF-β1 treatment increased the expression level of lncRNA-ATB. CONCLUSIONS Upregulation of lncRNA-ATB by TGF-b1 promotes migration and invasion of PTC cells.