OBJECTIVES: A recent study at Gastroenterology Unit of “Federico II” Naples University, showed in a 95 patient cohort that annually HBV surface antigen (HBsAg) quantification in patients receiving nucleo(t)side-analogues (NUC) antiviral therapy, with stable viral suppression, helps identifying patients achieving HBsAg seroconversion, allowing to stop NUC. However no cost analysis was available. The objective is to estimate the costs associated to introduction of yearly HBsAg monitoring test in routine clinical practice, estimating savings related to NUC discontinuation. METHODS: Data on resource consumption were retrospectively captured through patient chart abstraction in the same cohort of 95 patients, with a median treatment follow-up of 111 months (range 25–183 months). To estimate HBV drugs costs (lamivudine, tenofovir and entecavir) current ex-factory prices were used, while diagnostic and laboratory tests were valorised with national outpatient tariffs. For each determination of the HBsAg diagnostic test a price of €5.98 was used. Then we made an extrapolation from our initial data to a 10-year follow-up assuming the rate of seroconversion would remain stable over future years. RESULTS: The analysis shows that despite the increased costs related to HBsAg monitoring test in the cohort, and the seroconversion rate in only 4/95 patients, generated 2,606 saved days of NUC treatment, which has become unnecessary, representing €20,171 of total cost-saved. Simulating this cohort of patients in the next 10 years and assuming no changes for other variables (ie patients managements and cost of NUC), the introduction of the HBsAg test will generate €115,179 saving. CONCLUSIONS: Results of this preliminary analysis show that the systematic yearly HBsAg quantification monitoring test is a cost-saving strategy for the Italian healthcare system, when considering avoided NUC therapy. Future works should explore additional potential savings associated to reduction in others healthcare resources in HBV patients undergoing the test.