Introduction: Sleep disturbances are common among adolescents and are associated with elevated anxiety, and dificulties managing affect. Familial conlict is associated with both anxiety sensitivity and adolescent sleep disturbances. No work to date has examined how adolescent sleep disturbances may interact with anxiety sensitivity in relation to adolescent affective responding to parent-adolescent conlict. The current study was designed to address this gap in the literature by examining how adolescent sleep disturbances, anxiety sensitivity, conlict elicited anger, and conlict avoidance are associated. Method: Seventy-two American adolescents (n = 39 males) between the ages of 12 and 16 years (M age = 13.84, SD = 1.38) completed a baseline assessment as well as a well-validated motheradolescent laboratory-based conlict task. Results: For youth low in anxiety sensitivity, greater sleep disturbance related positively to conlict-elicited anger, which in turn predicted higher conlict avoidance. In contrast, this indirect effect was not signiicant for adolescents relatively higher in anxiety sensitivity. Instead, for these adolescents, increased sleep disturbances were associated with lower levels of conlict elicited anger. Conclusions: Results suggest that the effects of sleep disturbances on conlict elicited anger may vary as a function of adolescent anxiety vulnerability. These indings highlight the importance of considering the unique effects of sleep disturbances on adolescent affect as a function of adolescent anxiety vulnerability.Sleep and Affective Reactivity. Sleep disturbances are common and chronic among adolescents, and are associated with increased risk for a host of psychological and somatic issues (Roberts, Roberts,