The evidence-based guideline 'Diagnosis and treatment of abdominal aortic aneurysm' is applicable to all patients with an atherosclerotic fusiform or ruptured aneurysm of the abdominal aorta (AAA) and can be found on www.vaat-chirurgie.nl, click on Richtlijnen. An AAA with a diameter < 5.5 cm is treated conservatively and monitored by sonographic surveillance. All patients are advised secondary prevention with antiplatelet therapy, a statin, treatment of hypertension and smoking cessation. Depending on comorbidity, the indication for an operation is an AAA diameter of 5.5 cm. The anatomical characteristics of the AAA guides the choice for an open operation or endovascular aneurysm repair (EVAR). In view of the lower perioperative mortality, EVAR is the treatment of choice. Due to the high prevalence of AAA in siblings of patients with an AAA the screening of these family members should be considered. The minimum number of elective operations per hospital per year has been set at 15.