Seeking information about one's health is increasingly documented as a key coping strategy in health-promotive activities and psychosocial adjustment to illness. In this article, the authors critically examine the scientific literature from 1982 to 2006 on the concept of health information—seeking behavior (HISB) to determine its level of maturity and clarify the concept's essential characteristics. A principle-based method of concept analysis provides the framework for exploring the nature of HISB. The authors reviewed approximately 100 published articles and five books reporting on HISB. Although HISB is a popular concept used in various contexts, most HISB definitions provide little insight into the concept's specific meanings. The authors describe the concept's characteristics, contributing to a clearer understanding of HISB, and discuss operationalizations, antecedents, and outcomes of HISB. Such an analysis of HISB might guide further theorizing on this highly relevant concept and assist health care providers in designing optimal informational interventions.