Iodopovidone is an effective, safe, cheap, and easily available agent for pleurodesis. On the other hand, topical applications of iodopovidone may cause thyroid dysfunction. The purpose of this retrospective study was to determine the effects of intrapleural administration of iodopovidone on thyroid function. Twelve patients have undergone iodopovidone pleurodesis so far. A mixture of 20 ml 10% iodopovidone and 80 ml 0.9% saline solution was administered into the pleural cavity through the chest tube. Thyroid hormone (TSH, TT4, TT3, FT4, FT3) levels were routinely measured just before pleurodesis, and at the 24th and 72nd h of pleurodesis. No statistically significant alteration in thyroid function was determined (P>0.05). We did not observe any signs or symptoms of hyper- or hypothyroidism in any patient. Nine patients had a complete response to pleurodesis (75%). One patient who had undergone iodopovidone pleurodesis suffered from a moderate degree of transient chest pain. In conclusion, iodopovidone pleurodesis is safe and does not cause any thyroid dysfunction in normal adults.