Background: Cranial electrotherapy stimulation (CES) is a well-tolerated neuromodulation treatment with demonstrated trial efficacy in anxiety disorders. The aim of the current study was to demonstrate its clinical and cost effectiveness during and after CES in people with generalised anxiety disorder (GAD) who had not responded to low intensity psychological treatment in a routine health service. Methods: Consecutive sample of eligible patients with GAD waiting for individual cognitive behaviour therapy (CBT) selected from two publicly funded services in England. They received 60 minutes per day Alpha-Stim CES for 6-12 weeks. Primary outcome was remission on the GAD-7 scale at 12 and 24 weeks. Cost effectiveness was examined using a cost minimisation model of direct health costs. Results: Of 161 patients recruited, 72 (44.7%) and 77 (47.8%) achieved remission on the GAD-7 at 12 and 24 weeks respectively with 122 (75.8%) receiving at least 6 weeks CES. Mean (sd) GAD-7 score at baseline significantly improved from 15.77 (3.21) to 8.92 (5.42) and 8.99 (6.18) at 12 and 24 weeks respectively (p<0.001). 80 (49.7%) participants required further individual CBT. CES provided a saving of £540.88 per patient (95% CI -£327.12, £648.69). Limitations: Participants were not randomised and there was no control group. Only 48 (29.9%) participants completed every assessment. Conclusion: In patients with generalised anxiety disorder not responding to low intensity psychological treatment, 6-12 weeks daily Alpha Stim CES may be effective after treatment and 3 months later, thereby reducing the need for individual CBT and saving health costs.