Abstract: Polybrominated diphenyl ethers (PBDEs)are a class of flame retardants used in a variety of consumer products. In the past 25 years, PBDEs have become ubiquitous persistent organic pollutants. They have been detected in soil, air, sediments, birds, marine species, fish, house dust, human tissues, blood and breast milk. Concentrations of PBDEs are particularly high in breast milk and house dust, resulting in high exposure to infants. Laboratory data showed that PBDEs induced toxicity to thyroid gland including changing the levels of thyroid hormone and the shape and structure of follicular cells. Based on the toxicological researches and findings, we summarized their thyroid toxicity and possible toxicity mechanism, analyzed the existing problems in related research field, and discussed the future research directions on PBDEs.