Phospholipase C-gamma1 plays a central role in signal transduction, and it is important in cellular growth, differentiation, and proliferation. Human cholesteatoma in the middle ear is characterized by the presence of a keratinizing epithelium that is believed to have hyperproliferative properties. The purpose of this study is to elucidate the distribution of phospholipase C-gamma1 in cholesteatoma matrix and deep meatal skin with Western blot analysis and immunohistochemistry. In conclusion, overexpression of phospholipase C-gamma1 in cholesteatoma matrix suggests a possible derangement of enhanced growth signal transduction in keratinocytes.