Background. Marjolin's ulcer is a rare, aggressive cutaneous malignancy that arises primarily in burn scars but can occur in other types of scars. Squamous cell carcinoma is the most common variant, and while malignant degeneration usually takes a long time, it can develop acutely. Case Report. a 30-year-old man who developed Marjolin's ulcer acutely in a right postauricular scar after mastoidectomy and the incision and drainage of a mastoid abscess. To the best of our knowledge, this report is the first to describe a Marjolin's ulcer in a postauricular surgical scar. However, it has been reported in others areas in the head and neck. Conclusion. Marjolin's ulcer is most commonly observed after postburn scars, but it may be observed after any type of scars, as our patient developed an SCC with a postsurgical scar. Early diagnosis is essential, and a biopsy should be performed on any nonhealing wound or chronic wound that undergoes a sudden change. Tissue samples should be taken from both the centre and the margins of the wound.