Abstract: Background: Cognitive behavioral therapy for headache (CBT-HA) improves headache-related outcomes, but accessibility barriers limit its use. This pilot study evaluated the feasibility, acceptability and clinical signal of an interactive voice response (IVR)-delivered CBT-HA intervention for veterans with post-traumatic headache (PTH). Methods: A single-arm pilot trial was conducted with 18 veterans diagnosed with PTH. Participants completed a 10-week IVR-CBT-HA program. Outcomes were assessed at baseline, immediately post-treatment and one-month follow-up. Primary outcomes included changes in headache days, interference, disability, feasibility and acceptability. Results: Fifteen participants completed the study. Headache frequency, headache-related disability, depressive symptoms, anxious symptoms, sleep quality and headache catastrophizing were not statistically significant. Self-efficacy significantly improved from baseline to post-treatment (F(2,12)=8.71, p=0.001), and remained stable at follow-up. Participants reported high satisfaction with the intervention (27.73/32, SD=5.66) but low system usability (mean=20.83/100, SD=15.72). Study therapists rated the intervention as highly acceptable (acceptability of intervention: mean=4.83/5, SD=0.37) and feasible (feasibility of intervention measure: mean=4.92/5, SD=0.28). Interactive CBT for headache and relaxation training (i.e. iCHART) resulted in an approximately 33% cost savings compared to traditional CBT-HA. Conclusions: Asynchronous, IVR-delivered CBT-HA was feasible, acceptable and cost-effective for veterans with PTH. Although headache reductions were not statistically significant, self-efficacy improvements suggest long-term benefits. Future research should explore technology refinements and larger randomized trials. Trial Registration: ClinicalTrials.gov: NCT05093556 (registered 26 October 2021).