The purpose of this study was to validate the Spanish version of Motl and Conroy’s model of the Social Physique Anxiety Scale (SPAS–7). To achieve this goal, a sample of 398 secondary school students was used, and the psychometric properties of the SPAS–7 were examined through different analyses. The results supported the seven-item model, although the item 5 did not show any significant correlation with two items from this model and had a lower factor loading than the rest of items. The structure of the model was invariant across gender and Body Mass Index (BMI). Alpha value over .70 and suitable levels of temporal stability were obtained. Girls and students classified according to the BMI as overweight and obese had higher scores in social physique anxiety than boys and the group classified as underweight and normal range. The findings of this study provided reliability and validity for the SPAS–7 in a Spanish adolescent sample.