The objective of this study was to evaluate the effect on quality of life (QOL) of screening for abdominal aortic aneurysm (AAA) in a population-based AAA screening program. Twenty-four patients with screening-detected AAA and 45 controls with normal aortic diameter were studied in a prospective, controlled, population-based study. Prior to and 12 months after the ultrasonography examination, all participants completed Short-Form 36 and at 12 months, 10 AAA-specific questions were added. Comparisons were made between the two groups (AAA patients and controls), within each group, and between the groups and norms for the general Swedish population in the same age interval. Our results showed that screening for AAA results in impairment of QOL among those who have the disease and who suffered a low QOL prior to screening. Among those who had an age-adjusted normal QOL prior to screening and who were found to have the disease, and among those who were found to have normal aortas, no negative effect on QOL was observed. Thus, low QOL before screening is a possible risk factor for negative mental effects of diagnosing an AAA by screening.