BACKGROUND: Most measures of anxious avoidance are limited to disorder-specific mechanisms and ignore the measurement of courage/approach responding in confronting fearful situations. AIMS: The purpose of the present study was to construct and validate a self-report assessment of the tendency towards avoidant or approach responding in fearful situations, the Response to Fearful Situations Scale (RFSS). METHOD AND RESULTS: In Study 1 (n = 241), exploratory factor analysis resulted in two factors, avoidance and approach. Study 2 (n = 423) replicated the two-factor structure and established test-re-test reliability. In Study 3 (n = 44), the RFSS demonstrated predictive validity on a behavioural avoidance task. In Studies 4 (n = 253) and 5 (n = 256), the RFSS was associated with clinical symptoms above existing measures of avoidance. DISCUSSION: These results validate the use of the RFSS as a transdiagnostic measure of avoidance and approach.