Cases of human infestation by Fasciola hepatica are not uncommon in Spain and other European countries. We report our experience with 20 patients diagnosed from 1982 to 1991 and present a critical review of published cases from western countries. Because F. hepatica has a special tropism for the liver, abdominal pain, hepatomegaly, and constitutional symptoms are among the most common manifestations of acute-stage fascioliasis. However, in the chronic stage, biliary colic and cholangitis are the predominant manifestations. The clinical spectrum of fascioliasis is variable, and patients may present with extrahepatic abnormalities, such as pulmonary infiltrates, pleuropericarditis, meningitis, or lymphadenopathy. Therefore, a high index of suspicion is required to establish a correct diagnosis. Eosinophilia is the most frequent laboratory abnormality. The CT scan has become a useful technique in the diagnostic work-up. A definitive diagnosis may be established by the observation of parasite ova in the feces, but most cases may be diagnosed by serologic methods. Triclabendazole and bithionol are the most effective drugs against F. hepatica. The efficacy of praziquantel is controversial.