Marjolin ulcers are cancers, usually of squamous cell carcinoma pathology, that occur in scars or wounds. They are classically described in burn victims but can occur with other types of trauma and are rarely seen in association with bite wounds. Marjolin ulcers typically have a latent period of many years post-injury until the development of malignancy, but there are a few case reports of an exceedingly rare acute form. We present a case of a 78-year-old female who developed a Marjolin ulcer one month after sustaining a dog bite to the left index finger.