This paper explores consumers’ commitment to and conviction about their beliefs in the form of attitude certainty. Based on a review of past research, we present a new framework for understanding attitude certainty and how consumers’ attitude certainty is shaped by their resisting or yielding to persuasive messages, or even by their reflections on the evidence supporting their attitudes. We propose that attitude certainty is formed and changed largely through an attribution-based reasoning process linked to a finite set of distinct appraisals. Our framework is used to both organize past research and offer guidance for future research endeavors. In addition, we distinguish our framework of appraisal-based attitude certainty from past models in attitudes and persuasion research that have referenced or taken note of the attitude certainty construct. Implications and future directions for the study of consumer behavior are discussed.