Brunner's gland hamartoma is a rare duodenal tumor generally localized in the duodenal bulb. Normally assymptomatic, it might cause upper gastrointestinal bleeding or intestinal obstruction. The diagnosis is based on upper gastrointestinal endoscopic or barium examination findings, and its treatment includes surgical or endoscopic resection, with an optimum prognosis. We present the case of a 59-year-old woman who was admitted to the hospital with an upper gastrointestinal bleeding picture. Endoscopic examination showed an ulcerated polyp in duodenal bulb which was cut with polipectomy wire. Histological slides showed a parasitic granuloma within a Brunner's gland hamartoma. Skin prick test and specific IgE determination were positive for Anisakis. Up to our knowledge, this association has never been described before.