The Brugian filariasis in Korea was once endemic in several areas including Jeju-do and small remote islands located in the southwestern part of the Korean peninsula. But recently it has almost been controlled. The first patient was a 42-year-old man, who visited the hospital with the chief complaints of fatigue, jaundice and edema on the right low extremity. Examination of a peripheral blood smear revealed non-megaloblastic macrocytic anemia, thrombocytopenia and eosinophilia, and a parasite, which was identified as microfilaria of Brugia malayi on the glass slide of blood obtained from the patient at midnight. The second patient was a 23-year-old man, who visited the hospital with the chief complaints of cough, sputum and fever. A parasite resembling that of the first patient was found in a peripheral blood smear accompaning neutrophilia. No more parasites, however, were found in the peripheral blood obtained from the patient at midnight. These two clinical cases of Brugian filariasis indicate that the clinical laboratory in Korea should be able to detect microfilariae for the diagnosis of filariasis.