This study is a validation of the Spanish version of the Social Phobia and Anxiety Inventory using a nonclinical sample (198 participants) and a clinical sample (72 participants with social phobia). The factor structure and concurrent validity with Fear of Negative Evaluation and Social Avoidance and Distress scales were analyzed. The Social Phobia and Anxiety Inventory demonstrated good concurrent validity, showing statistically significant relationships with Fear of Negative Evaluation and Social Avoidance and Distress. Results confirmed the rationale for the division of the SPAI into two subscales. Results also demonstrated the utility of the Social Phobia and Anxiety Inventory for differentiating between a nonclinical sample and participants with a social phobia, and its adequate reliability.