The authors report a case of acute small bowel occlusion related to anisakis. This parasitis is due to ingestion by man, an unusual host, of a nematode of "anisakis" type at larva stage, a parasite to be found in numerous species of raw or home-processed fish. The parasite whose symptomatology is aspecific, can be located on the whole digestive tube. Diagnosis suggested by medical inquiry along with eosinophily, can be confirmed by serology and discovery of the parasite after anatomo-pathologic analysis. Medical treatment consisting in associating anti-parasite medicines with corticoids in certain cases, is recommended in diffuse forms and allergic signs of disease. Surgical complications make the laparotomy necessary for appropriate diagnosis and curing of the patient. Increasing frequency of this pathology shows the importance of prophylactic measures such as: abstaining from raw or home-processed fish, cooking fish at a temperature of 60 degrees C, deep-freezing fish at a temperature of -20 degrees C for 24 h at least, before eating it raw.