BACKGROUND Circular RNAs are important regulators in human cancers, including thyroid carcinoma. The circ_0067934 RNA is reported to participate in hepatocellular carcinoma, esophageal squamous cell carcinoma, and lung cancer. Whether it regulates thyroid carcinoma remains unclear. The purpose of this study was to research potential mechanisms of circ_0067934 in thyroid tumors to provide potential new diagnostic and treatment targets. MATERIAL AND METHODS The expression level of circ_0067934 in thyroid tumors, adjacent tissues, and cell lines was measured by qRT-PCR. The Kaplan-Meier survival curve analysis was used to explore the relationship between circ_0067934 level and survival time of patients. Circ_0067934 was knocked down to research its functional role in thyroid tumors. Cell proliferation was detected by CCK-8 (cell counting kit-8) assay. Migration and invasion were analyzed by Transwell assay. Western blot was applied to analyze the expression of epithelial-mesenchymal-transition (EMT) and PI3K/AKT related proteins. RESULTS Compared with adjacent tissue, circ_0067934 was highly expressed in thyroid tumors. Circ_0067934 expression level was highly expressed in thyroid tumor cell lines. Patients with high expression of circ_0067934 showed lower survival rates. Knockdown of circ_0067934 inhibited cell proliferation, migration, and invasion and also promoted apoptosis. In addition, circ_0067934 knockdown inhibited EMT and PI3K/AKT signaling pathways. CONCLUSIONS circ_0067934 could improve the development of thyroid carcinoma by promoting EMT and PI3K/AKT signaling pathways.