Seborrheic keratosis (SK) is a common skin tumor that is typically benign but can be indistinguishable from malignant tumors. Current treatment methods carry risk of scarring and discoloration and are not always effective. We present the case of a 68-year-old woman with an SK lesion on her right cheek that had been growing for the previous 10 years. During an in-patient water-only fasting and exclusively whole-plant-food dietary intervention, the SK lesion began regressing until complete resolution was observed two weeks after her departure.