The Cancer Information Service (CIS) of the National Cancer Institute (NCI) is a health communications program that disseminates information through two channels: to individuals through a toll-free telephone service and to organizations (serving primarily underserved populations) through an outreach program. People call the 1-800-4-CANCER line to meet a variety of information needs. The information specialists who respond to these calls are prepared to answer questions ranging from cancer prevention to early detection, treatment, and survivorship. In a 1996 random sample survey, 2,489 callers were asked why they called, how they valued the information, and what health-related actions they took or decisions they made since their call. Results show the CIS is highly valued by its users, with satisfaction high across gender, age, education, and racial/ethnic groups. While differences in satisfaction were observed by caller type and subject of inquiry, nearly all respondents reported that contact with the CIS increased knowledge, provided reassurance, and influenced decisionmaking and health behavior. Overall, 95% were satisfied with CIS information, 98% trusted the information, 92% reported an increase in knowledge, 69% felt reassured, and 73% said the information helped them to better cope with their concerns. Eight out of 10 callers reported the information they received had a positive impact, with 56% reporting taking a positive health action. Results demonstrate that health communications programs like the CIS can fill information gaps consumers must bridge to make informed health care decisions and can play an important public health role in motivating people to take actions to reduce risks and/or make decisions that lead to improved health status.