Ferric reducing antioxidant power (FRAP), myeloperoxidase (MPO) activity and the levels of protein thiols and carbonyls were estimated in the blood samples of thyroid cancer patients (n = 20) before and after thyroidectomy, as well as in healthy controls (n = 10) to study the extent of damage caused by tumor tissue proliferation-induced oxidative stress and to ascertain that oxidative stress levels drop, when there was no proliferation. A significant decrease (p<0.001) in the levels of serum protein thiols and FRAP as well as a significant increase (p<0.001) in the levels of protein carbonyls and MPO activity in the blood of thyroid cancer patients before surgery was observed as compared to healthy controls. All the parameters studied also showed a significant difference (p<0.001) in their respective levels in thyroid cancer patients, pre- and post-thyroidectomy. These findings present the role of oxidative stress as a pathological implication of thyroid cancer.