In an effort to better understand individuals' use of information in risky situations, in this article we propose a new variable, information sufficiency, as an important component of people's information-seeking behaviors. We surveyed residents of 2 Great Lakes cities to test the ability of a group of factors often employed in risk communication studies to predict information sufficiency, defined as a person's sense of how much information he or she needs to cope with a risk. We found that 2 predictors of this perceived gap in information were an individual's worry about the risk and the perception that others would expect one to keep abreast of information about the risk.