The Social Phobia Inventory (SPIN) is a 17-item self-rated scale designed to assess the spectrum of fear, avoidance, and physiological symptoms associated with social phobia. It was developed to address the limitations of existing self-rated scales, which often fail to capture the full range of symptoms. The SPIN was validated through various psychometric properties, including test-retest reliability, internal consistency, convergent and divergent validity, and factorial analysis. The scale demonstrated good reliability, with a Spearman correlation coefficient of 0.89 in group III and 0.78 in group IV. Internal consistency was also strong, with Cronbach's alpha ranging from 0.87 to 0.94 for social phobia subjects. Convergent validity was supported by strong correlations with established measures such as the Liebowitz Social Anxiety Scale (LSAS), the Brief Social Phobia Scale (BSPS), and the Marks Fear Questionnaire (FQ). Divergent validity was demonstrated by weak correlations with measures of general health and disability. Factor analysis identified five factors, including fear, avoidance, and physiological symptoms. The SPIN was also shown to be sensitive to changes in symptoms over time and to differentiate between treatment effects. A score of 19 was found to be a good threshold for distinguishing between subjects with and without social phobia. The SPIN has solid psychometric properties and shows promise as a tool for screening and assessing treatment response in social phobia. However, further research is needed to evaluate its application in diverse populations, including children, ethnic minorities, and non-English speakers.The Social Phobia Inventory (SPIN) is a 17-item self-rated scale designed to assess the spectrum of fear, avoidance, and physiological symptoms associated with social phobia. It was developed to address the limitations of existing self-rated scales, which often fail to capture the full range of symptoms. The SPIN was validated through various psychometric properties, including test-retest reliability, internal consistency, convergent and divergent validity, and factorial analysis. The scale demonstrated good reliability, with a Spearman correlation coefficient of 0.89 in group III and 0.78 in group IV. Internal consistency was also strong, with Cronbach's alpha ranging from 0.87 to 0.94 for social phobia subjects. Convergent validity was supported by strong correlations with established measures such as the Liebowitz Social Anxiety Scale (LSAS), the Brief Social Phobia Scale (BSPS), and the Marks Fear Questionnaire (FQ). Divergent validity was demonstrated by weak correlations with measures of general health and disability. Factor analysis identified five factors, including fear, avoidance, and physiological symptoms. The SPIN was also shown to be sensitive to changes in symptoms over time and to differentiate between treatment effects. A score of 19 was found to be a good threshold for distinguishing between subjects with and without social phobia. The SPIN has solid psychometric properties and shows promise as a tool for screening and assessing treatment response in social phobia. However, further research is needed to evaluate its application in diverse populations, including children, ethnic minorities, and non-English speakers.