Background: The present study examined the effectiveness of a transdiagnostic prevention programme, Super Skills for Life (SSL), in children with anxiety problems. SSL is based on the principles of cognitive-behaviour therapy (CBT), behavioural activation, social skills training, and uses video-feedback and cognitive preparation as part of the treatment. Methods: Participants were 61 primary school children, aged 8-10 years, who were referred by their teachers as having significant anxiety problems. Children were video-recorded during a 2-min speech task in sessions 1 and 8, and during a social interaction task. All the children completed measures of anxiety symptoms, social skills, and self-esteem before and after participating in the 8-week SSL and at the 6-months follow-up assessment. Results: Anxiety symptoms were significantly reduced at post-test and follow-up assessments. SSL also had a positive effect on hyperactivity, conduct, and peer problems although it took longer for these effects to occur. Behavioural indicators of anxiety during the 2-min speech task decreased, indicating that the independent raters observed behavioural change in the children from pre-treatment to follow-up. Boys had higher overall behavioural anxiety during the 2-min speech task at all three assessment periods, specifically showing higher lip contortions and leg movement than girls. Limitations: The present study used an open clinical trial design, had small sample size, and did not use structured diagnostic interview schedules to assess anxiety disorders. Conclusions: This study provides preliminary empirical support for the effectiveness of SSL in children with anxiety problems.