Being able to evaluate the accuracy of an informant is essential to communication. Three experiments explored preschoolers' (N=119) understanding that, in cases of conflict, information from reliable informants is preferable to information from unreliable informants. In Experiment 1, children were presented with previously accurate and inaccurate informants who presented conflicting names for novel objects. 4-year-olds--but not 3-year-olds--predicted whether an informant would be accurate in the future, sought, and endorsed information from the accurate over the inaccurate informant. In Experiment 2, both age groups displayed trust in knowledgeable over ignorant speakers. In Experiment 3, children extended selective trust when learning both verbal and nonverbal information. These experiments demonstrate that preschoolers have a key strategy for assessing the reliability of information.