Sleep disturbance is a typical health problem of the elderly. The purpose of this study was to explore the extent of sleep disturbance of Korean elderly, and to identify the influencing and predicting factors. A total of 15216 subjects were interviewed. To measure the quality of sleep, "The Korean Sleep" Scale was used, and as influencing factors on sleep, physical health, emotional and social activity variables were included. In this study, the percentage of a change of sleep pattern was 59.2%, and it was higher in elderly women and in above 80 yrs. But only 10.4% of subjects regarded a change of sleep pattern as a problem, and it was higher in elderly women. Total sleeping time was shorter in female and it was shortest in 65-69yrs. The higher age, the presence of Ds, the longer sickdays, the lower level of ADL and IADL, the more depressive, the more tedious during the daytime, and the less frequent engagement in exercise, the lower quality of sleep measured by KSS. Predicting variables of quality of sleep included depression, boredness during the daytime, sex, the presence of Ds, IADL, the frequency of exercise during a week, and age. These seven variables explained 13% of total quality of sleep. The extent of change of sleep pattern in the elderly is very high. Continuous efforts to increase quality of sleep of the elderly by intervening in factors influencing quality of sleep are needed.