The present study was conducted as an extension of an earlier study which examined the prevalence of social anxiety among elementary school children. This study, as a further step of the first study, tried to find out the causes of social anxiety among elementary grade children. The objective of the study was to find out the major causes of social anxiety in elementary grade children. Structured interview schedules were used to collect data from 30 boys and 30 girls from Central Model School and Government Girls High School, Samanabad respectively. These boys and girls had already been identified as having social anxiety in the previous study. The findings of the present study indicated that the major cause of social anxiety among both boys and girls was their personal thinking factor.