Prospective clinical plasma biomarker studies in abdominal aortic aneurysm (AAA) pathogenesis have been hampered by the need for very large cohorts and long follow-up time. The main aim of the present study was to evaluate the association of adrenomedullin, a cardiovascular (CV) stress marker, and incident AAA risk. Prospective longitudinal cohort of middle-aged individuals from the CV cohort of the Malmö Diet and Cancer Study (n = 5551; 1991-1994) was assessed. Plasma concentrations of midregional proadrenomedullin (MR-proADM), C-reactive protein (CRP), and conventional risk factors were measured at baseline. Incidence of AAA was studied up to December 31, 2013. Cumulative incidence of AAA was 1.5% (men 2.9%, women 0.5%). Mean age of individuals with incident AAA was 59.7 years at study entry, and AAA was diagnosed on average 14 years later. Adjusting for age, gender, smoking, body mass index, hypertension, diabetes mellitus, and CRP, MR-proADM (hazard ratio: 1.28; 95% confidence interval: 1.01-1.62) was independently associated with incident AAA. The plasma biomarker MR-proADM seems to be a marker of AAA risk, implying that AAA development may be driven by long-standing CV stress on the aortic wall.