Cognitive interest is a motivation to acquire information that is caused by a cognitive and emotional state of uncertainty about the meaning of a text. It can, therefore, be expected to increase if a text raises an issue in readers' mind without resolving it. In support of this expectation, the results of 3 experiments show that the readers' cognitive interest in narratives increased when they read contradictory outcomes, which call for missing explanations, or when they draw hypothetical predictions, which call for missing confirmations of the anticipated events. The increases in cognitive interest were observed before full comprehension was achieved. Therefore, the cognitive interest does not rely on the "postdictability" of what is read. As a motivation to suppress uncertainty, cognitive interest would selectively enhance attention and inferences, with the pleasurable aim of resolving issues. The embodiment of cognitive interest through emotions of negative and positive valences is also discussed. (Contains 4 tables.)