Purpose: To experimentally test whether chronic sleep restriction, which is common among adolescents, is causally related to poor learning, inattentive behaviors, and diminished arousal in a classroom-like situation. Methods: Sixteen healthy adolescents underwent a sleep manipulation that included, in counterbalanced order, five consecutive nights of sleep deprivation (6 hours in bed) versus five nights of healthy sleep duration (10 hours in bed). At the end of each condition, participants viewed educational films and took related quizzes in a simulated classroom. Eight participants also underwent video and electroencephalography monitoring to assess levels of inattentive behaviors and arousal, respectively. Results: As compared with the healthy sleep condition, sleep-deprived participants had lower quiz scores (p = .05), more inattentive behaviors (p < .05), and lower arousal (p = .08). Conclusions: These pilot data complement previous correlational reports by showing that chronic sleep restriction during adolescence can cause inattention, diminished learning, and lowered arousal in a simulated classroom. (C) 2010 Society for Adolescent Health and Medicine. All rights reserved.