Study objectives: The objectives of the study were to investigate the effects of 36 h of sleep deprivation on the discrete mood states of anger, depression, anxiety, confusion, fatigue, and vigour in healthy adolescents. Method: Twelve healthy adolescent good sleepers (six male), aged 14-18 years (M = 16.17, standard deviation (SD) = 0.83), spent three consecutive nights in the sleep laboratory of the Centre for Sleep Research: two baseline nights with 10-h sleep opportunities and one night of total sleep deprivation. Every 2 h during wakefulness, they completed the Profile of Mood States - Short Form. Mood across two baseline days was compared to mood at the same clock time (0900 h to 1900 h) following one night without sleep. Results: The subscales of depression, anger, confusion, anxiety, vigour, and fatigue were compared across days. All mood states significantly worsened following one night without sleep. Females showed a greater vulnerability to mood deficits following sleep loss, with greater depressed mood and anxiety following sleep deprivation only witnessed among female participants. While both males and females reported more confusion following sleep deprivation, the magnitude of this effect was greater for females. Conclusions: This study provides empirical support for the notion that sleep loss can causally affect mood states in healthy adolescents, with females having heightened vulnerability. Understanding the detrimental effects of insufficient sleep during adolescence is important, as it is a stage where sleep loss and mood dysregulation are highly prevalent. These findings escalate the importance of promoting sleep for the well-being of adolescents at this critical life phase.