Eggs of Echinostoma sp. were found from two patients who were hospitalized between Oct. and Dec. 1985. Single dose of 10 mg/kg of praziquantel was prescribed to each patient and after purgation with magnesium salt seven and two adult worms of Echinostoma cinetorchis in respect were recovered from patients. The first case was a 54-year-old male residing at Chungju city in Chungbuk province. He was hospitalized because of severe weight loss and frequent urination. The second case was a 71-year-old male residing at Chungsun-kun in Kangwon province, and hospitalized due to suspected lung cancer. The average size of the eggs found in the stools was 98 x 63 micrometer (the first case) and 100 x 67 micrometer (the second case) respectively, and total nine worms collected were identified as E. cinetorchis.