Models of cognitive processing in anxiety disorders state that socially anxious children display several distorted cognitive processes that maintain their anxiety. The present study investigated the role of social threat thoughts and social skills perception in relation to childhood trait and state social anxiety. In total, 141 children varying in their levels of social anxiety performed a short speech task in front of a camera and filled out self-reports about their trait social anxiety, state anxiety, social skills perception and social threat thoughts. Results showed that social threat thoughts mediated the relationship between trait social anxiety and state anxiety after the speech task, even when controlling for baseline state anxiety. Furthermore, we found that children with higher trait anxiety and more social threat thoughts had a lower perception of their social skills, but did not display a social skills deficit. These results provide evidence for the applicability of the cognitive social anxiety model to children.