BACKGROUND: In the Republic of Korea, there had been no reports about indigenous malaria cases since 1984 until a vivax malaria case was detected in 1993. Thereafter fram 1993 to 1996, 486 malaria cases were reported. Most of the patients were soldiers in the northern militarized zone. However, since 1997, several patients with malaria were detected in Kang Hwa where there had previously been no report of malaria cases. It is our intent to report the 16 cases diagrnosed in Kang Hwa Community Hospital from January 1, 1997 to August 10, 1998. METHODS: Medical records of the malaria cases from January 1, 1997, to August 10, 1998 in Kang Hwa Community Haspital were reviewed. All of the patients had no histories of traveling abroad, drug abuse or blood transfusion. They were all civilians. Laboratory studies including blood cell count, routine chemistry and platelet-associated IgG(PAIgG) and abdominal sanography were taken. RESULTS: All of the patients were diagnosed with malaria by blood smears. Common symptams were fever(100%), headache(94%), rigors(81%), myaJgia(56%), nausea or vomiting(44%), alternate day fever (25%), left flank pain(19%), diarrhea(13%), and abdominal pain(13%). Splenomegaly was detected in 92% of cases by sonography. Laboratory findings included leukopenia(37.5%), anemia(37.5%) and thrombocytopenia(81.3%). Platelet-associated IgG was elevated in 1 of 5 thrombocytopenic patients who had had the laboratory study performed. All recovered withaut complications. CONCLUSIONS: Cases of indigenous malaria have been progressively increasing in the Republic of Korea. Fortunately, patients responded well to treatment, but continued interest will be required in the future.