Objective: We present the first published case of large foreign body reaction to Biodesign (Cook Medical, Bloomington, IN), an acellular otologic graft matrix derived from porcine small intestinal submucosa, after use in tympanoplasty surgery in a patient without previous exposure to meat products. Methods: A single case report of a 39-year-old female who developed tinnitus, ear drainage, and large fibrotic mass in external auditory canal and extending into middle ear after Type I medial graft tympanoplasty with Biodesign Graft. Left endoscopic microdissection and resection of the tympanic membrane and middle ear fibrotic mass were performed. Main findings: Surgical excision of the fibrous mass required extensive microdissection to ensure preservation of the ossicles and chorda tympani. Postoperatively, hearing improved and otalgia and otorrhea resolved. Conclusions: We report the first case of post-tympanoplasty reaction with the use of Biodesign acellular porcine graft in a patient with no previous known exposure to meat products. Although this presentation appears to be rare, it reinforces the need for careful patient selection and counseling around the use of porcine or other foreign grafts.