This study examined the association between worry and fearful responding to a 3-min voluntary hyperventilation procedure. Participants were 160 adolescents (71 females) between the ages of 12 and 17 years (M=14.92 years). After accounting for the significant effects of state anxiety and anxiety sensitivity, results indicated that pre-challenge levels of worry indexed by the Penn State Worry Questionnaire-Child Version predicted post-challenge anxiety and intensity of panic symptoms. Results are discussed in terms of the role of worry in relation to panic-relevant emotional vulnerability among youth.