Diphyllobothrium latum infection in human is not common in China and only 15 cases have been reported since 1927. We document a case of Diphyllobothrium latum infection caused by the ingestion of raw fish in a 23-year-old woman in Dalian (Liaoning Province), and diphyllobothriasis latum in China is briefly reviewed. The patient experienced abdominal discomfort for about 6 months with a history of discharging proglottids in the feces. The morphologic characteristic of the gravid proglottids and eggs were identified as that of Diphyllobothrium latum. The patient was treated with pumpkin seed powder (100g) and betel nut(100g) on an empty stomach. The majority of reported human cases occurred due to the ingestion of raw or uncooked fish, such as pikes, burbots, trouts, perch and salmons. The patient is the first case reported in Dalian (Lianning Province).