In France, Corsica is one of the regions most affected by the fallout from the Chernobyl accident. Based on the scientific knowledge available at the time, it was deemed essential to focus on thyroid cancers. A study was conducted to estimate the incidence of thyroid cancer on the island for the periods 1998–2001 and 2002–2006. The study included patients residing in Corsica who were diagnosed with thyroid cancer between 1998 and 2006. Data were collected from the national database of the Medical Information Systems Program (PMSI) and from Long-Term Illness (ALD) designations for thyroid cancer managed by the health insurance funds. Cases were validated after reviewing the medical records of patients who underwent surgery. During the study period, 342 cases of thyroid cancer were recorded in Corsica, primarily affecting women and relatively young individuals. The incidence of thyroid cancer was high but stable among men and increased slightly among women, particularly between 2002 and 2006. However, the situation in Corsica regarding thyroid cancer in terms of incidence and clinical characteristics is not exceptional and is similar to that in other French departments located both east and west of mainland France. (R.A.)