This study examines a model which simultaneously contains two paths between waiting line and purchase intention: one tested the positive effect of waiting line through consumers’ perceived quality, whereas another one go through consumers’ emotional state to test the negative effect of waiting line on purchase intention. To further understand perceived quality, the study divided perceived quality into perceived product quality and perceived service quality. The study used restaurants in the experiment. Results indicated that although long waits in line will directly increase both consumers’ product quality perception and negative emotions, the total indirect effects on purchase intention are still significantly positive. For consumers’ perceived service quality, long waiting situations have no such effect on it. Significant results from a moderation analysis also shown that consumers in low-level knowledge settings are more influenced by waiting lines than those in high-level knowledge settings when they make the product’s quality-related judgment. However, the level of consumer knowledge does not moderate the relationship between waiting lines and service quality.