With the current trend of alarming rise in obesity rates, the health impacts of excess weight will become more apparent. While an increased incidence of cardiovascular disease and diabetes mellitus has been well documented, the association between obesity and carcinogenesis is just being appreciated and is receiving increasing attention. The current review focuses on the evidence linking thyroid cancer with obesity. We conclude that there is sufficient evidence that obesity can predispose to an increased risk of thyroid cancer in both men and women. This population-based association is mainly explained at a biological level through specific obesity-related endocrinopathies.