Endovascular aortic repair (EVAR) has been accepted as the first treatment option in most patients with infrarenal and thoracic aortic aneurysms. Advantages include its minimal invasive approach and lower risk of mortality and morbidity compared to open surgical repair. In patients with complex aneurysms involving side branches, novel techniques of parallel, fenestrated and branched endografts have expanded the indications of EVAR. Preoperative planning is of paramount importance to achieve technical success and to minimize risks of these procedures. In most centers, anatomical measurements are based on helical computed tomography angiography and/or magnetic resonance angiography. This article summarizes the most important aspects on planning standard and complex EVAR to treat aortic aneurysms and dissections.