BACKGROUND: To analyze the clinical, bacteriologic, diagnostic and therapeutic features of patients with Fasciola hepatica (FH) in our hospital. PATIENTS AND METHOD: We reviewed all the patients with a diagnosis of fascioliasis from 1975 to 1999 in the Aranzazu Hospital in San Sebastián (Guipúzcoa, Spain). Diagnosis was made by direct vision of adult parasites during surgery and/or the presence of ova in stool examinations and/or positive serologic tests in patients with symptoms consistent with parasitosis. RESULTS: Thirty-seven patients were included (23 men and 14 women), aged 19 to 71 years. Ingestion of watercress was confirmed in 27. Seven cases occurred as part of familiar outbreaks. Thirty-two were in the liver invasive stage and in 5 the biliary tree was invaded. The most common features were eosinophilia (91.8%), malaise and weight loss (75.6%), elevated alkaline phosphatase (74.2%), and abdominal pain (72.9%). Adult worms in the biliary ducts were observed in 3 patients and ova in feces were observed in 6. In 13 of 27 patients indirect hemagglutination test was ( 1/1,280. Data significant to confirmation of liver involvement were provided by laparoscopy in 12 of 13 patients and by imaging techniques in 13 of 31 patients. Four patients had cholelithiasis and of these, 2 also showed adult parasites in the common bile duct. Three patients underwent surgery. Therapy with dehydroemetine and/or bithionol was followed by complete remission in 30 patients, although 6 required repeat treatment cycles. The remaining 4 patients were cured by praziquantel. CONCLUSIONS: Most of the patients in these series reported consumption of watercress and all patients showed the symptoms typical of parasite disease. Imaging techniques proved to be of great utility in confirming the diagnosis of hepato-biliary disease. In most of the patients therapy with dehydroemetine and/or bithionol (in one or several cycles) was followed by complete remission.