RESUMEN
A 16-year-old boy had eaten Chinese freshwater crabs soaked in liquor in October 2000, and the left pleural effusion was pointed out on chest X-ray films at a regular medical checkup at school in June 2002. Since his father and friends had suffered from Paragonimiasis Westermani and had been treated in January 2001, the patient agreed to immunoserological examination, and Paragonimiasis Westermani was diagnosed. After drainage of pleural effusion, the patient was treated with praziquantel for three days at a daily dosage of 75 mg/kg, but without effect. The patient received drainage of pleural effusion again, and was treated with praziquantel for 3 days at a daily dosage of 75 mg/kg in a series of three treatments at three week interval. After that, improvement of the disease was achieved.