BACKGROUND: The latest update to the Australian adenoma surveillance guideline in 2018 introduced a novel risk stratification system with updated surveillance recommendations. The resource implications of adopting this new system are unclear. METHODS: We studied data from 2443 patients undergoing colonoscopies, in which a clinically significant lesion was identified in their latest, or previous procedure(s) across five Australian hospitals. We excluded procedures with inflammatory bowel disease, new or prior history of colorectal cancer or resection, inadequate bowel preparation, and incomplete procedures. Old and new Australian surveillance intervals were calculated according to the number, size, and histological characteristics of lesions identified. We used these data to compare the rate of procedures according to each guideline. RESULTS: Based on the procedures for 766 patients, the new surveillance guidelines significantly increased the number of procedures allocated an interval of one year (RR 1.57, p = 0.009) and ten years (RR 3.83, p <0.00001), and reduced those allocated to half a year (RR 0.08, p = 0.00219), three years (RR 0.51, p <0.00001), and five years (RR 0.59, p <0.00001). Overall, this reduced the relative number of surveillance procedures by 21% over ten years (25.92 vs 32.78 procedures/100 patient-years), which increased to 22% after excluding patients 75 or older at the time of surveillance (19.9 vs 25.65 procedures/100 patient-years). CONCLUSION: The adoption of the latest Australian adenoma surveillance guidelines can reduce demand for surveillance colonoscopy by more than a fifth (21-22%) over ten years. This article is protected by copyright. All rights reserved.