Anisakidosis is the infestation of man by the larval stage of the parasite Anisakis simplex. A history of ingestion of raw or undercooked fish up to 48-72 hours before the onset is highly orientative. Based on the location of the lesions, various types of human anisakidosis have been identified: gastric, intestinal and luminal forms constitute the majority of cases and symptoms often mimic a variety of acute conditions such as gastritis, acute appendicitis, diverticulitis, or ileitis. We present a case of a young woman admitted to our department with acute abdominal pain. A history of raw fish ingestion was recorded. The patient was submitted to explorative laparoscopy in which an oedematous, thickened segment of ileum was observed. Therefore a small laparotomy was performed, followed by resection of the thickened ileum. The histological examination revealed transmural inflammation with marked infiltration of eosinophils. High levels of total IgE and Anisakis simplex-specific IgE were recorded. Anisakidosis is an underestimated cause of acute abdomen, and should be taken into consideration as a differential diagnosis in these conditions. Nevertheless, in most cases, the correct approach could prove difficult, because surgery may be necessary in these settings, allowing the diagnosis only by histological and parasitological investigation of the resected specimen.