Tympanic membrane (TM) perforations heal by reepithelialization and fibrous layer proliferation. The rat TM model may be used to study growth factors that promote epithelialization and fibroblast proliferation, such as epidermal growth factor (EGF) and fibroblast growth factor (FGF). The authors previously evaluated the effects of FGF on tympanic membrane perforations and showed an enhanced rate of wound healing with preservation of normal structure and function. The same model was used to test keratinocyte growth factor (KGF, also called FGF-7). This growth factor has been shown to stimulate the migration and proliferation of keratinocytes. This is the first study investigating KGF in the tympanic membrane perforation model. Our results show that in contrast to FGF and EGF, KGF does not enhance the rate of wound healing, but rather results in a more organized wound repair process.