Recent paradigm shift in health care calls for more attention to patient preferences. The Health Information Wants (HIW) Questionnaire measures patients' preferences (desires) for health information and participation in decision-making. It has parallel items in seven corresponding areas of information and decision-making (diagnosis, treatment, laboratory test, self-care, complementary and alternative medicine, psychosocial, and health care provider). A pilot study was conducted to generate preliminary data about the psychometric property of this instrument, the relationships between information and decision-making preferences in each of the seven areas, and the relationships among Internet use, age, and preferences for each type of health information and decision-making. The results show that the HIW Questionnaire has strong reliability and validity. After controlling for gender, education, perception of severity, and health, the overall preferences for health information and decision-making were positively correlated. Multilevel modeling analysis results showed that age was negatively related to the overall preference ratings. The differences in decision-making preference ratings between young and older adults were greater than those in information preference ratings. Internet use frequency was not significantly related to preference ratings. The relationships examined varied across the seven subscales (e.g., on the diagnosis subscale, age was positively associated with diagnostic decision-making preferences). These findings have implications for a better understanding of patient preferences, patient-provider relationships, and the quality of health care.