Abstract: Brucellosis is the most common zoonotic infectious disease. Though rare, cardiovascular involvement is the main cause of death for brucellosis. Infectious endocarditis is most common, but infectious aneurysm is very rare. This article summarizes the clinical treatment of a case of brucellosis with left common iliac artery dissection and pseudoaneurysm based on the analysis on the clinical symptoms and signs, imaging changes, and laboratory test abnormalities. The imaging examination showed that there were saccular processes in the arteries of the abdominal lesion and calcified shadows in the arterial wall. Brucella serological examination confirmed brucellosis with left common iliac artery dissection and pseudoaneurysm. After the standard anti-infection treatment, the systemic inflammation was controlled. After discharge, the clinical symptoms and signs of brucellosis disappeared, and the color ultrasound showed that the pseudoaneurysm was reduced and cured. It is necessary to improve clinicians' understanding of brucellosis infectious aneurysm to reducee missed diagnosis and misdiagnosis.