Accurate personality judgments are important for successful interpersonal interactions. Because millions of people use the Internet everyday to create and maintain interpersonal relationships, the current study investigated interpersonal perception in Internet chat rooms. Participants were 156 undergraduate students who interacted in chat rooms for 15 min either one-on-one or in groups of six. Using the Social Relations Model (Kenny, 1994), it was found that in one-on-one interactions, judges were able to achieve consensus for the targets' traits of extraversion, agreeableness, and openness. For extraversion and openness, this agreement corresponded with targets' self-perceptions. Unlike research using face-to-face interactions, consensus was highest and assimilation was lowest when participants interacted one-on-one. Judges in group interactions tended to like the targets less and viewed them less favorably across all personality traits than did judges in one-on-one interactions. Targets' self-reported personality had little predictive power in determining who was liked in Internet chat rooms. However, targets' prior chat room experience was consistently found to be a moderate predictor of likability. Interpersonal perception is crucial to our ability to complete daily social activities. We must be able to perceive something about the people we interact with in order to know whether we should respond to them, trust them, or even befriend them. For this reason, many researchers during the past several decades have focused on determining the reliability and accuracy with which people perceive others' personalities during face-to-face interactions (Funder, 1999;Kenny, 1994). While the majority of this research has demonstrated that people tend to be reliable and accurate judges of personality, it is unclear whether less direct forms of communication (e.g., Internet chat rooms) render enough information for individuals to make reliable judgments.