Seventy one agoraphobie patients with panic attacks, and 54 social phobics, diagnosed according to DSM III criteria have been compared. The two groups were balanced for age, sex, and educational level. Statistical comparisons of clinical, and psychometric variables differentiated the two groups. Panic attacks frequency characterized the agoraphobie patients, while very low assertion scores on Radius’ Assertiveness Schedule characterized social phobies. An association with simple phobias was more frequently found in agoraphobic patients. Comparable levels of generalized anxiety and avoidance were found in the two groups. MMPI mean profile was more disturbed in social phobics. Psychasthenia scale, and anxiety index, were significantly higher in social phobics. Social phobias started earlier, but these patients sought treatment later, and took less psychotropic medication. There was no correlation between assertiveness and panic attacks frequency in the two sub-samples. Principal components analysis of MMPI scales and Assertiveness Schedule confirmed the heterogeneity of the two syndromes. Results are discussed in regard of the extensive use of panic attacks as a general model of anxiety.