The primary foci of the study were exploration of the linkage between cognitive and autonomic inflexibility of worry and generalized anxiety disorder (GAD) and examination of the effects of an analog cognitive restructuring task on this relationship. Cardiac responses of GAD and non-GAD participants were measured to examine the sympathetic and parasympathetic effects of worry and cognitive challenge. Diagnostic groups of undergraduate students were determined via administration of a structured interview, yielding a GAD group (n=16) and a control group (n=19) of individuals without GAD, depression, or panic disorder diagnoses. Cardiac autonomic responses were acquired via electrocardiogram during rest, worry, and cognitive challenge conditions by an experimenter blind to diagnosis. Metrics were compared between the two groups and across the three conditions. Individuals diagnosed with GAD did not differ significantly from controls on autonomic indices. Worry was associated with significantly decreased parasympathetic influence and increased sympathetic activity. Cognitive challenge did not result in significant increased cardiac responsivity. The results indicate that worry behavior is associated with decreased vagal activity, suggest a linkage between autonomic and cognitive inflexibility, and provide further suggestions for improving protocols to assess the autonomic effects of cognitive therapy techniques.