Objectives: The aim of this research was to study and compare cognitive biases towards the negative social and non-social events in adolescents with high and low social anxiety.

Method: In a descriptive cross-sectional study 125 boys and girls in first and second year of counseling and guidance school. 41 adolescents (18 boys, 23 girls) with high social anxiety and 84 adolescents (44 boys, 40 girls) with low social anxiety were assessed by the Social Anxiety Scale for Children, Children Depression Inventory and the Probability/Cost Questionnaire for Children (PCQ-C). Data were analyzed through t test, multivariate Covariance analysis and correlation analysis.

Results: Adolescents with high social anxiety overestimated the cost and probability of negative social events compared to adolescents with low social anxiety, even after controlling for depression syndrome (p<0.001). No statistically significant differences were noted between the two groups in the probability scores of the non-social events. The effect of gender and its interaction in the groups over the probability and cost of the negative non-social events also was not statistically significant.

Conclusion: Adolescents with high social anxiety show more bias in the interpretation of negative social events than their peers with low social anxiety.