Objective In the current economic context, it is critical to ensure that eating disorder (ED) treatments are both effective and cost-effective. We describe the impact of a novel clinical pathway developed to better meet the needs of autistic patients with EDs on the length and cost of hospital admissions. Method The pathway was based on the Institute for Healthcare's Model of Improvement methodology, using an iterative Plan, Do, Study, Act format to introduce change and to co-produce the work with people with lived experience and with healthcare professionals. We explored the change in length and cost of admissions before and after the pathway was introduced. Results Preliminary results suggest that the treatment innovations associated with this pathway have led to reduced lengths of admission for patients with the comorbidity, which were not seen for patients without the comorbidity. Estimated cost-savings were approximately £22,837 per patient and approximately £275,000 per year for the service as a whole. Conclusion Going forward, our aim is to continue to evaluate the effectiveness and cost-effectiveness of investment in the pathway to determine whether the pathway improves the quality of care for patients with a comorbid ED and autism and is good value for money.