We report on a case of thrombosis of the left common iliac artery following anterior lumbar interbody fusion (ALIF) of L4-5 in a 79-year-old man with no previous medical problems, including peripheral vascular disease. After completing the ALIF procedure, the surgeon could not feel the pulsation of the left dorsalis pedis artery, and the oxygen saturation ($SaO_2$) had fallen below 90% from pulse oxymetry on the left great toe. Thrombectomy was successfully performed after confirming the thrombus in the left common iliac artery using Computed Tomography (CT) angiography. Thrombosis of the common iliac artery is very rare following ALIF. However, delayed diagnosis can lead to disastrous outcome. Although elderly patients have no cardio-vascular disease or vessel calcification in pre-op evaluation, the possibility of a complication involving L4-5 should be considered.