Misfolding poses a serious problem in the biotechnological field in obtaining the active protein from inclusion bodies. Here we show that high temperature increases the refolding yield of reduced lyosyzme by a simple dilution method. The refolding yields at 98 degrees C were three times higher than those at 20 degrees C in the solutions tested, which is related to the fact that the thermally unfolded state of lysozyme is a more productive form for folding than the denaturant-induced fully unfolded state. The thermal-assisted refolding could be used for various reduced and denatured proteins as a result of its simplicity and low cost.