In two experiments, we examined the effects of text messaging during lecture on comprehension of lecture material. Students (in Experiment 1) and randomly assigned participants (in Experiment 2) in a text message condition texted a prescribed conversation while listening to a brief lecture. Students and participants in the no-text condition refrained from texting during the same lecture. Postlecture quiz scores confirmed the hypothesis that texting during lecture would disrupt comprehension and retention of lecture material. In both experiments, the no-text group significantly outscored the text group on the quiz and felt more confident about their performance. The classroom demonstration described in Experiment 1 provides preliminary empirical evidence that texting during class disrupts comprehension in an actual classroom environment. Experiment 2 addressed the selection bias and demand characteristic issues present in Experiment 1 and replicated the main findings. Together, these two experiments clearly illustrate the detrimental effects of texting during class, which could discourage such behavior in students.