Objective: Intolerance of uncertainty (IU) is an important concept in eating disorders (ED). Cognitive, emotional, and behavioral features of IU amongst individuals with and without ED were investigated. Method: Participants completed the intolerance of uncertainty scale (IUS) and four versions of a data-gathering task varying in difficulty/uncertainty, and rated their Beads task experience. Results: ED groups had significantly higher IUS scores than healthy controls (HC). Bulimia Nervosa (BN) participants requested more cues than HC and Anorexia Nervosa (AN) participants before making decisions. ED groups found the task more distressing than HC participants, with those with BN feeling more uncertain and less confident in their decisions, and those with AN attributing greater importance in making the correct decision. Discussion: While both ED groups reported raised IUS scores only BN participants engaged in an elevated evidence requirement data gathering style. Future research might benefit from further exploration of the role of perseverative processes in BN. (C) 2011 Published by Elsevier Ltd.