Transdiagnostic interventions present pragmatic benefits in treatment dissemination and training of mental health professionals when faced with emotional disorders such as anxiety and depression. Excessive worry is a common feature across emotional disorders and represents an ideal candidate target for transdiagnostic intervention. The current pilot trial examined the efficacy of a behavioural activation treatment for worry (BAW) in a community population. 49 individuals experiencing excessive worry were randomised to waitlist or BAW receiving an 8 week group based intervention. Results demonstrated that BAW was successful in reducing excessive worry, depressive symptoms, cognitive avoidance, Intolerance of Uncertainty and improving problem solving orientation. Twice as many individuals showed clinically significant reductions in excessive worry after treatment compared to the waitlist control. Despite limitations to sample size and power, this study presents promising support for BAW as a practical transdiagnostic treatment for worry.