ObjectiveBenefits of abdominal aortic aneurysm (AAA) screening are dependent on high attendance. We sought to examine self-reported reasons for non-attendance and to describe differences in socioeconomic factors, comorbidities, and risk factors between non-attenders and attenders. MethodsAll non-attenders to screening at Oslo University Hospital in 2022 were contacted by letter/phone with a questionnaire about reasons for non-attendance, socioeconomic factors, comorbidities, and risk factors. For all the attenders in 2022, information on comorbidities and risk factors was available in the screening database, and a randomized selection (1:1 to non-attenders) was contacted by phone to obtain information on socioeconomic factors. ResultsThere were 259 non-attenders and 1483 attenders to screening in 2022. Data on comorbidities and risk factors were available for all attenders. For the 259 men contacted in each group, the response rate was 39% for the non-attenders and 72% for the attenders. Among non-attenders who replied, 57% did not remember receiving an invitation or forgot the appointment; however, 76% replied that they would attend AAA screening if they were to receive a second invitation. Compared with attenders, non-attenders were more likely to live alone (41% vs 22%; P = .001), receive home nursing (10% vs 0.5%; P < .001), and to smoke (27% vs 14%; P < .001), and they were less likely to have a higher education (54% vs 71%; P = .004). ConclusionsContacting non-attenders yielded a reply from only 39%; thus, reasons for non-attendance are still obscured among the majority. Among those who replied, the main reasons for non-attendance were not remembering receiving an invitation or forgetting the appointment—modifiable factors that could be accounted for in the invitation process. There were significantly more smokers (the strongest modifiable AAA risk factor) among non-attenders, indicating that non-attenders would especially benefit from AAA screening.