Purpose: Fatty accumulation in the liver, or steatosis, is common after systemic chemotherapy, and has been considered a major risk factor for adverse outcome after hepatic resection, but its true impact is unclear. This study evaluates effects of hepatic steatosis on outcome after liver resection for malignancy in a large group of patients. Methods: All patients with underlying steatosis who underwent hepatic resection for cancer at Memorial Hospital from 12/91-9/01 (N=319) were identified from a prospective database. Histology was re-reviewed by a pathologist, and non-tumor bearing liver was stratified by degree of fatty change according to a 4-point scale: 1, focal steatosis (N=139); 2, diffuse but mild (N=85); 3, diffuse (N=59); 4, severe (N=36). Cases were further stratified as follows: mild steatosis, 1-2 (N=224, 70%); marked steatosis, 3-4 (N=95, 30%). Clinical outcome was correlated with histology and results were compared to a cohort of patients with normal livers (N=160) matched statistically by age, diagnosis and extent of resection. Results: Operative procedures consisted of 164 trisegmentectomies, 134 lobectomies and 181 resections of less than one lobe. Median operative time was 250 min (range, 38-555) and median blood loss was 640 cc (range, 20-6000). Morbidity was 49% and operative mortality was 3.5%. On multivariate analysis, marked steatosis was associated with increased complications but did not impact on perioperative mortality (Table). Morbidity and mortality were unaffected by mild steatosis. Additionally, overall survival of patients with normal parenchyma (43 months) was no different from that of patients with marked steatosis (44 months, p=0.8 by log-rank test). Conclusions: The presence of marked steatosis was associated with increased complications after hepatic resection, but had no impact on operative mortality or long-term survival. Steatosis alone, therefore, should not preclude a potentially curative hepatic resection, if clinically warranted.