Because online customer complaint behavior influences not only customer loyalty, but also other customers’ purchase intentions, it is important to examine the antecedents of customer complaint behavior. Previous research on antecedents of customer complaint behavior focuses on personal traits and post-purchase perceptions, while this paper focuses on online customer pre-purchase perceptions. In an online market, trustworthy online retailers send signals to separate themselves from retailers who are untrustworthy in the eyes of customers. However, untrustworthy online retailers can mimic trustworthy online retailers’ behavior by sending similar signals without providing services indicated by the signals. Relying on expectation-confirmation theory and signaling theory, we study conceptually and empirically how signal credibility influences online customer complaint intentions. Signal credibility reflects customer pre-purchase perceptions of the quality of an online retailer. Data were collected from a Chinese online B2C market, Tmall.com. The results from this data indicate that signal credibility has a direct negative influence on online customer complaint intentions. Furthermore, signal credibility can moderate the relationship between customer satisfaction with post-purchase services and online customer complaint intentions.