It is important for tourism online marketplace to ensure potential tourists continually use their services as an alternative to find and purchase travel packages. Hence, the factors that influence customers' negative behaviors, such as switching intention, complaints, and negative WOM are critical to be understood. This research explores the antecedents of tourist customers' negative behaviors, using expectancy disconfirmation theory (EDT) as its theoretical lens, and IS success model as the initial quality precursors. The research gathered 81 sample, whom were active users of a tourism eMarketplace from the greater Jakarta region. The quantitative data was then analyzed using PLS-SEM. The results showed that quality disconfirmation served as a key antecedent of customers' negative emotions, which in turn will lead to their negative behaviors. More specifically, disconfirmation in information quality may prompt customers' regret, which then leads to negative WOM. Finally, systems quality disconfirmation triggers customers' anger, which then elicits a number of negative behaviors such as switching intention, complaints and negative WOM.