Previous research into the relationship between knowledge level and anchoring effects has led to mixed conclusions. This paper presents four studies that used a diverse set of stimuli and paradigms to further investigate this relationship. In Study 1, greater knowledge was associated with smaller anchoring effects—both when knowledge was measured using subjective self-assessments and when using an objective knowledge measure. In Study 2, participants from the USA and India tended to exhibit smaller anchoring effects when answering questions about their own country as compared with questions about the other country. In Study 3, higher knowledge was associated with smaller anchoring effects when examined at an idiographic level. Finally, in Study 4, providing participants with information designed to increase their knowledge led to a decrease in anchoring effects. The consistency of the results across our four studies provides evidence that anchoring effects are moderated by knowledge level in many situations. Copyright © 2012 John Wiley & Sons, Ltd.