Two patients who developed malignant neoplasms in scars (Marjolin's ulcers) are described in this report. The first patient developed a squamous cell carcinoma in the site of a chronic, draining urinary fistula. The malignancy later metastasized. The second patient developed a squamous cell carcinoma and a basal cell carcinoma in a scar from a burn and a keratoacanthoma in a scar from a vaccination. The history of the eponym “Marjolin's ulcer” is traced and it is pointed out that Marjolin did not describe the condition he is eponymously credited with, but that the false ascription to him arose over time.