The assessment of social anxiety through self-report measures tends to involve the more widely used questionnaires at international level: SPAI, LSAS-SR, SPIN, SPS, and/or SIAS. In this study, these questionnaires have been applied to university students, with an examination made of their factor structure, reliability and internal consistency. The best factor solutions for these self-report measures have been as follows: SPAI, six factors; LSAS-SR Anxiety subscale, five factors; SPIN, three factors; SPS, three factors, and SIAS, three factors. The reliability and internal consistency of these questionnaires is adequate. A comparison is made between the different solutions obtained by the various questionnaires, and a critical analysis is conducted of the factor results recorded in the light of the dimensional structure of social anxiety established for a new self-report measure, namely, the “Social Anxiety Questionnaire for Adults” (SAQ-A30). Finally, consideration is given to the relevance of these analyses for a more efficient assessment of social anxiety both in terms of the general population and at clinical level.