Fibroblasts are mesenchymal cells and secrete a non-rigid extracellular matrix that is rich in type I and/or type III collagen. They are responsible for much of the synthesis of extracellular matrix in connective tissues and play major roles in wound healing. Many diseases involve fibroblasts; either because their etiology involves fibroblasts or because of the fibrosis that accompanies damage to other cell types. The thyroid is easily susceptible to inflammatory autoimmune diseases which can result in tissue damage. It suggests that thyroid fibroblasts may play an important role in regulating thyroid function and response to disease. Human Thyroid Fibroblasts are usefull tools for understanding physiological and pathophysiological relevance in Thyroid gland function and disease.