Hepatic artery thrombosis (HAT) and other vascular complications are significant causes of morbidity after liver transplantation. Although cigarette smoking increases the risk of vascular complications after renal transplantation, its impact after liver transplantation remains unknown. Between May 1995 and April 2001, 288 liver transplantations were performed in 263 patients. Vascular complications developed in 39 patients (13.5%) (arterial complications, 28 patients [9.7%]; venous complications, 11 patients [3.8%]). Patient demographics, comorbid illnesses, and risk factors were analyzed using the Mann-Whitney U test, Chi-squared test, and Fisher's exact test. In patients with a history of cigarette smoking, incidence of vascular complications was higher than in those without history of cigarette smoking (17.8% v 8%, P =.02). Having quit cigarette smoking 2 years before liver transplantation reduced the incidence of vascular complications by 58.6% (24.4% v 11.8%, P =.04). The incidence of arterial complications was also higher in patients with a history of cigarette smoking compared with those without such history (13.5% v 4.8%, P =.015). Cigarette smoking cessation for 2 years also reduced the risk of arterial complications by 77.6% (21.8% v 5.9%, P =.005). However, the incidence of venous complications was not associated with cigarette smoking. Furthermore, there was no significant association between development of vascular complications and all other characteristics studied. Cigarette smoking is associated with a higher risk for developing vascular complications, especially arterial complications after liver transplantation. Cigarette smoking cessation at least 2 years before liver transplantation can significantly reduce the risk for vascular complications. Cigarette smoking cessation should be an essential requirement for liver transplantation candidates to decrease the morbidity arising from vascular complication after liver transplantation.