This paper summarizes our experience of five cases of sick-sinus syndrome, hospitalized at Presbyterian Medical Center in Jeonju from January, 1980 to January, 1983. Diagnosis was made depending on clinical symptoms, physical examination, EKG and provocative test with atropine sulfate. The etiologies of 4 cases were as follows: coronary disease, hypertension, myocarditis, coronary disease with hypertension; but, the etiology of one case was not clear. Symptoms, including syncope, dizziness, and palpitation subsided after implanting the temporary pacemaker. A permanent pacemaker was implanted in all but one case, who had myocarditis.