Introduction: Population based screening for AAA reduces aneurysm-related mortality and all-cause mortality. The AAA screening program in Stockholm started 2010, inviting men born 1945 to a one-time examination with ultrasound. The efficacy of a screening programs depends not only on the participations-rate but on the quality of the surveillance program and the results after surgery. The aim of this study was to describe the natural history for men participating in screening, including drop-out rates and mortality in surveillance and results after surgery. In addition we present AAA treatment rates and ruptures among non-participants in our county. Methods: A population based screening program inviting 65-year-old men started in 2010 in Stockholm County (2.3 million inhabitants). The screening program is centralized and is administered using a web-based database. Patients' demographics are collected prospectively at the first visit (index) and all surveillance visits are registered. All men diagnosed with AAA 2010-2016 were included (n=662) and compared with a control group (n=237). The time of follow-up was 12-84 months. Medical charts and Swedvasc registry data were analyzed for aortic repair in all men born 1945-1951. Results: The participation in screening was 78%, the AAA-prevalence was 1.2% (n=672). Treatment rates correlated with high aortic size index (ASI) and aortic diameter, 22,5 % of men with an AAA detected in screening were treated for intact AAA. The 30-day mortality for the 152 treated men was 0%. During the study period, 35 men in surveillance died (5.2 %), non-AAA related causes (82,9 %) dominated, followed by unknown causes among 4 men (11.4%), and 2 (5.7%) possibly AAA related deaths. The rupture rate in participants vs non-participants was lower (0.0036% vs 0.096%). Conclusion: The high participation rate and low drop-out rate confirm acceptability of population based screening. The efficacy of the program is shown by the much higher rupture rate among the non-participating men. Implementing complimentary surveillance methodologies, such as ASI, should be investigated further. Disclosure: Nothing to disclose