PurposeConsumer response to merchandise shortage in the online supply chain outlet is an interesting and important issue for e‐vendors because of the high risk associated with the online environment. The purpose of this study is to examine the effects of the online environment on consumer out‐of‐stock behaviors. In addition, it aims to examine the relative impact of non‐web site situational factors on consumer out‐of‐stock behavior.Design/methodology/approachThe study proposed an expectation confirmation‐disconfirmation framework based on the utility maximization principle in consumer research. This framework was validated with data from online shopping transactions gathered in two field studies.FindingsThe occurrence of a stock‐out had a pervasive negative impact on consumers' assessment of their online transactional experience and repurchase intentions. Furthermore, item substitution behavior was positively linked with merchandise information content, vividness of web site content, and service speed and a few situational factors. Overall, it was found that consumers' reaction to the “shock” effect of a stock‐out was best explained by an expectation confirmation‐disconfirmation model rather than a performance‐only or expectation‐only model.Research limitations/implicationsWhile the focus on the total expectation confirmation‐disconfirmation process limited the scope of the study to a single stock‐out event, future research should examine multiple stock‐out events to further validate the proposed framework.Practical implicationsManagers can take advantage of the positive linkage between web site design features and item substitution behavior by tracking the online consumers' expectation confirmation‐disconfirmation evaluative process and its effect on how consumers respond to high priced versus low priced items during a stock‐out event. Design features for low priced items such as CDs and books require product specific information to reduce item switching or exit from the e‐supply chain during a stock‐out event.Originality/valueScholars need a systematic framework for examining consumer response to a stock‐out that is applicable in the e‐commerce context because of the effects of abundant information access, low switching cost and the high service expectations of online customers.