The Anxiety Symptoms Interview (ASI) is a diagnostic instrument designed to identify agoraphobia (with and without panic attacks), panic disorder, social phobia, and obsessive compulsive disorder according to DSM-III criteria. The present study evaluated the diagnostic validity of this instrument by examining the extent to which ASI diagnoses assigned to 73 clinic patients agreed with diagnoses determined by clinicians. Most kappa coefficients and other concordance indicators were in the acceptable range or above, a finding that held for diagnoses overall and for specific diagnoses of agoraphobia with panic attacks, social phobia, and obsessive compulsive disorder. However, none of the 73 patients had clinician-assigned diagnoses of panic disorder (that is, without agoraphobia) or agoraphobia without panic. Limitations and applications of the ASI are discussed.