Panic attack symptomatology was investigated in 212 panic disorder patients (60 men, 152 women) using the Panic Attack Questionnaire, Feelings of helplessness and thoughts of escape had the highest mean severity ratings, but are not currently listed in the DSM-III-R. The DSM-III-R symptoms labeled choking or smothering sensations, paresthesias, nausea, and chest pain had low severity ratings. Evidence was obtained for a three-factor model of panic symptomatology consisting of dizziness-related symptoms, cardiorespiratory distress, and cognitive factors. These results provide only limited support for the current DSM-III-R symptom structure, and support the notion that panic disorder is a heterogeneous condition.