E-commerce service failures have been the bane of e-commerce, compelling customers to either abandon transactions entirely or switch to traditional brick-and-mortar establishments. Yet, there is a paucity of studies that investigates how such failures manifest on e-commerce websites and their impact on consumers. This paper, therefore, synthesizes extant literature on e-service and system success to arrive at a novel classification system that delineates e-commerce service failures into information, functional, and system categories, each with its own set of constituent dimensions. Extending expectation disconfirmation theory (EDT), we further distinguish among disconfirmed outcome, process, and cost expectancies as major consequences of e-commerce service failures. A theoretical model of e-commerce service failure classifications and their consequences was constructed together with testable propositions that relate the three failure categories to consumers’ disconfirmed expectancies. Finally, we explore the validity of our theoretical model based on descriptive accounts of actual occurrences of e-commerce service failures and their corresponding consequences. Consistent with our theoretical model, information and functional failures were found to be associated with disconfirmed outcome and process expectancies respectively. System failures, on the other hand, do not affect consumers’ disconfirmed expectancies, thereby contradicting our predictions. Post hoc analysis on constituent dimensions of information, functional, and system failures yielded additional insights on the preceding observations.