Eighty treatment-seeking adults age 60 or over with panic disorder, generalized anxiety disorder, and mixed anxiety states (generalized anxiety with panic attacks, panic disorder with secondary generalized anxiety) completed a clinical assessment and battery of self report measures. Several hypotheses were tested from the domains of distinguishing symptoms, associated features, and rates of comorbidity with other disorders. Greater between- than within-group variance was found on a subset of measures suggesting that the distinction between GAD and PD is generally valid in the older adult population. Higher scores on measures of sympathetic arousal, agoraphobic avoidance, and rates of comorbid somatization disorder and alcohol dependence distinguished those with PD from those with GAD. Higher scores on measures of depression and hostility, but not trait anxiety or worry, distinguished the GAD group. Results indicate that distinguishing features of GAD and PD in older treatment-seeking adults may be fewer and slightly different from those of younger adults.