Thyroid cancer is a common endocrine malignancy. The tumorigenesis of thyroid tumours has been identified in recent years, including numerous genetic alterations and several major signalling pathways. However, the molecular mechanisms involved in thyroid cancer metastasis remain controversial. Studies in thyroid cancer metastasis suggested that reactivation of several pathways, including epithelial to mesenchymal transition and microenvironment change, may be involved in thyroid cancer migration. The previously identified thyroid oncogenes, BRAF, RET/PTC and Ras, play important roles in regulating the metastatic process. Here, we review the recent knowledge eon molecular mechanisms involved in thyroid cancer metastasis.