OBJECTIVE: This study aims to investigate the role of BRAF-activated long non-coding RNA (BANCR) in papillary thyroid carcinoma (PTC) progression and its association with clinical and molecular characteristics. METHODS: Sixteen PTC patients were stratified into four groups (PTC, HT, HT-LNM, and PTC-LNM) based on cervical lymph node metastasis and concurrent Hashimoto's thyroiditis (HT) to explore BANCR expression and its relationship with immune-related factors and tumor microenvironment (TME). Functional assays, including Transwell invasion, colony formation, and CCK8 were performed to evaluate the biological effects of BANCR in PTC cell lines. Bioinformatics analysis further identified BANCR-related pathways and clinical relevance. RESULTS: BANCR expression was significantly reduced in PTC tissues compared to normal thyroid tissues and was inversely correlated with tumor grade, lymph node metastasis, and T stage. Overexpression of BANCR in PTC cell lines inhibited proliferation, invasion and migration. Bioinformatics analysis demonstrated significant associations between BANCR and immune cell infiltration, immune-related genes, and stromal scores. CONCLUSIONS: BANCR acts as a tumor suppressor in PTC, suppressing tumor growth and metastasis. These findings provide insights into BANCR's potential as a prognostic marker and therapeutic target in PTC.