This thesis is a quantitative research which focuses on patterns of sickness and health service utilization by the elderly, including related factors such as sex, age group, marital status, etc. Data used in this study was secondary data from the Kanchanaburi Demographic Surveillance System : DSS, Round 2 (2001). The subjects were people aged 60 years and over. The dependent variable was health service utilization and the independent variables were sex, age group, marital status, family size, household structure, education, occupation, average income per head, urban or rural residence, nature of household location and sickness characteristic, diseases, symptoms, and accidents. The analysis employed percentage and Chi-Squares value of crosstabulation, including Multi-nominal Logistic Regression when testing factors related to health service utilization. It was found that the elderly health service utilization mostly depends upon sickness characteristics such as diseases, symptoms, and accident. The factors related to health service utilization by the elderly were sex, age group, urban and rural residence, and sickness characteristics. Female elders were more likely to visit government hospital and private hospitals or clinics more than male elders. On the contrary, males were more likely to buy medicine at drug stores than females. The very old (70 years and over) visited government hospitals and health centers more than the less old (60-69 years), and their families participated in decision-making on health service utilization more. The elderly who lived in the rural and urban areas had equal access to health services from government hospitals because they had the right to use or not use their government health insurance cards of the top five diseases, it was found that the majority of the elders with common cold choose to buy medicine at drug stores because of personal beliefs and the convenience. The elders with heart disease, diabetes, blood pressure, and stomachache/ gastritis/ infected intestine chose to use government hospitals because more often. The elders ill with symptom groups were more likely to buy medicine at drug stores because of personal beliefs and the convenience. The elders who were injured from accidents were highly likely to visit government hospitals because of the seriousness of their condition. This recommended that Kanchanaburi province prepares suitable health service resources that fit the characteristics of elders. Furthermore increased knowledge about the common cold in order to give the rightly care is needed. Besides it is important to give elders who have headache/migraine and dizziness, fainting, and epilepsy access to government health service resources.