The aneurysms of the internal iliac artery are rare and very often asymptomatic. Because of the anatomic location of this artery, it can be difficult to diagnose this kind of aneurysm, when isolated. Frequently it is diagnosed in consequence of aneurysmatic complication, such as rupture and/or impending rupture. In this work we report our experience concerning 6 cases of ruptured aneurysm of the internal iliac artery, observed in 5 patients. In three of these cases the lesion was isolated. In two cases the patients had already been operated on for abdominal aortic aneurysm, 4 and 6 years before. All the five patients were operated on. In 5 cases we ligated the aneurysm, without using any vascular graft. In one case where the external iliac artery was involved, we used a vascular graft between the common iliac and common femoral artery, in order to repair the vascular axis. One case of mortality was observed and a rare complication occurred in one case. An 83-year-old man treated in emergency for ruptured aneurysm of the left internal iliac artery, with regular post-operative course, was hospitalized again 24 days later with sepsis and pain in the left lower abdomen. A CT scan and a following urography showed a urinary fistula probably due to an ischemic necrosis of a segment of the ureter. A percutaneous nephrostomy has been performed and the patient successfully discharged.