Life hassles have been implicated in both the formation and maintenance of psychosis symptoms. However, little is understood about the mechanism through which these stressors impact on psychosis. The current study proposed experiential avoidance (EA), a psychological coping style that is a central focus for change in Acceptance and Commitment Therapy (ACT), as a potential mediator of the link between life hassles and both the emergence and maintenance of delusional ideation. Participants were recruited to a non-clinical sample (N=133) and a clinical sample of psychosis patients (N=100). All participants completed a self-report questionnaire including a measure of delusions and delusional distress (Peters Delusions Inventory), life hassles (Survey of Recent Life Experiences) and EA (Acceptance and Action Questionnaire-II). Mediation testing (bootstrapping) indicated a significant mediation effect of EA in the relationship between life hassles and both delusions and delusional distress, in both clinical and non-clinical samples. The findings suggest that individuals (irrespective of their diagnostic status) with a tendency to suppress or avoid unwanted thoughts are significantly more likely to experience distressing delusions in response to stressful life occurrences. The use of ACT and Cognitive Behavioural Therapy to reduce EA in those at risk of emerging delusions and in patients with an already established psychosis is discussed.