This study investigated the effect of teacher misbehavior on student affect for the teacher and teacher credibility. Participants completed an Affect Toward Teacher Scale and a Source Credibility Scale in reference to one of four experimental conditions. The first two research questions examined the effect of misbehaviors on student affect for the teacher. Each misbehavior type was shown to have a significant impact on student affect for the teacher. Teacher "offensiveness" was found to impact affect the most. The second and third research questions examined the effect of misbehavior on teacher credibility. Credibility was significantly impacted by each individual type of misbehavior, with competence impacted the most by "incompetence," and caring and trustworthiness impacted the most by "offensiveness."