The purpose of this study was to identify information seeking practices of older people regarding disease treatment and their desire for participation in decision-making. The participants were 165 people, 65 years or older, living in Seoul. The tool was the Autonomy Preference Index developed by Ende et al.(1989), having two scales on information seeking and desire for participation in decision-making that was revised by this investigator by adding questions. The results are summarized as follows: 1. The average score for information seeking regarding disease treatment by these older people was a comparatively high with a score of 74.9 (possible range 0.0 to 100.0). 2. Desire by them to participate with the physician in decision-making regarding disease treatment had a mean score of 45.1 (possible range 0.0 to 100.0). 3. The average score for desire for participation in decision-making with the family regarding disease treatment was 67.2 points(possible range 0.0 to 100.0). Because many older people desire to receive information about disease treatment, the medical team should provide information to their satisfaction. The medical team should include in the decision-making process not only the family or the guardian of the older people but also the older people themselves and encourage them to express their thoughts. Ethically, Health professionals should offer an opportunity in which decision-making can meet each person\'s unique desire.