Extending previous work, we conducted two studies concerning the toxic influences of experiential avoidance (EA) as a core mechanism in the development and maintenance of psychological distress, and disruption of pleasant, engaging, and spontaneous activity. Of particular interest was whether EA accounted for relationships between coping and emotion regulation strategies on anxiety-related pathology (Study 1) and psychological distress and hedonic functioning over the course of a 21-day monitoring period (Study 2). In Study 1, EA mediated the effects of maladaptive coping, emotional responses styles, and uncontrollability on anxiety-related distress (e.g., anxiety sensitivity, trait anxiety, suffocation fears, and body sensation fears). In Study 2, EA completely mediated the effects of two emotion regulation strategies (i.e., suppression and reappraisal) on daily negative and positive experiences and was associated with diminished daily positive affective experiences and healthy life appraisals, diminished frequency of positive events and more frequent negative life events, and greater negative affective experiences. The present data show that cognitive reappraisal, a primary process of traditional cognitive-behavior therapy, was much less predictive of the quality of psychological experiences and events in everyday life compared with EA. Further consideration of experiential avoidance as a generalized diathesis and toxic process will be useful in improving our understanding of the etiology, phenomenology, and treatment of anxiety conditions, general human suffering, and disruptions in hedonic capacity.