Despite epidemiological reports indicating an association between social anxiety disorder (SAD) and cannabis use disorders (CUD), there is a paucity of research exploring the nature of this relationship. The present investigation examined potential moderators of this relationship that are consistent with a tension-reduction model of addiction. Specifically, physiological reactivity to stress and perceived coping with stress were evaluated as moderators of the relation between symptoms of SAD and CUD. Physiological (SCR) and subjective (perceived coping) responses to unpredictable white noise bursts were collected from non-clinical participants (n=123). Lifetime symptoms of CUD and anxiety disorders were assessed using a structured diagnostic interview. CUD symptomatology was associated with symptoms of SAD but not with symptoms of any other anxiety disorder. Only perceived coping to unpredictable stimuli moderated the relationship between SAD and CUD symptoms. Findings are discussed in the context of tension-reduction models of co-occurring social anxiety and problematic cannabis use.