This study presents the development and validation of a scale for Primary Education students that measures social well-being. A seven-factor structure was defined, with the factors being: achievement, cooperation, cohesion, coexistence, attitude towards school, attitude towards diversity and solidarity. 14 experts from independent European universities participated in the validation process of the scale. A substantial degree of agreement was reached by the experts (Fleiss’ kappa = .74). The 38-item scale showed considerable reliability (Cronbach’s alpha =.91). The confirmatory factor analysis confirmed the original seven-factor structure with consistent goodness and badness of fit indexes. Responses by 486 students from five different schools in 3rd to 6th grades (ages 9 to 12) were analysed by factors, gender, age and schools. Strong relationships were found between several factors. The promising results in this study suggest that this scale may be suitable for an international audience regardless of the participants’ gender, age or school.