Background: The pervasive tendency to avoid perceived risks has been recently implicated in the maintenance of anxiety pathology, and more specifically, social phobia. Social anxiety symptoms are thus hypothesised to be associated with a global risk-avoidant decision-making bias. Aim: This study investigated: (1) the relationship between risk-avoidance and social anxiety symptoms using both self-report and behavioural measures of risk-taking; and (2) whether risk-avoidance mediates the relationship between a dispositional vulnerability to anxiety (Behavioural Inhibition System [BIS] sensitivity) and social anxiety symptoms. Method: Fifty-five undergraduate students completed self-report measures assessing for social anxiety symptoms, risk-taking across various domains, and BIS sensitivity. Risk-avoidance was also assessed using a behavioural computer task. Results: As hypothesised, risk-avoidance correlated significantly with both social anxiety and BIS. Multiple regression analyses revealed that risk-avoidance served as a partial mediator between BIS and social anxiety. Conclusion: These results confirm the hypothesised relationship between BIS, risk-avoidance, and social anxiety symptoms. Risk-avoidance is one possible mechanism by which personality characteristics may be linked to anxiety pathology.