Objective The effects of obesity in liver transplantation remain controversial. Earlier institutional data demonstrated no significant difference in postoperative complications or 1-year mortality. This study was conducted to test the hypothesis that obesity alone has minimal effect on longterm graft and overall survival. Methods A retrospective, single-institution analysis of outcomes in patients submitted to primary adult orthotopic liver transplantation was conducted using data for the period from 1 January 2002 to 31 December 2012. Recipients were divided into six groups by pre-transplant body mass index (BMI), comprising those with BMIs of <18.0 kg/m2, 18.0-24.9 kg/m2, 25.0-29.9 kg/m2, 30.0-35.0 kg/m2, 35.1-40.0 kg/m2 and >40 kg/m2, respectively. Pre- and post-transplant parameters were compared. A P-value of <0.05 was considered to indicate statistical significance. Independent predictors of patient and graft survival were determined using multivariate analysis. Results A total of 785 patients met the study inclusion criteria. A BMI of >35 kg/m2 was associated with non-alcoholic steatohepatitis (NASH) cirrhosis (P < 0.0001), higher Model for End-stage Liver Disease (MELD) score, and longer wait times for transplant (P = 0.002). There were no differences in operative time, intensive care unit or hospital length of stay, or perioperative complications. Graft and patient survival at intervals up to 3 years were similar between groups. Compared with non-obese recipients, recipients with a BMI of >40 kg/m2 showed significantly reduced 5-year graft (49.0% versus 75.8%; P < 0.02) and patient (51.3% versus 78.8%; P < 0.01) survival. Conclusions Obesity increasingly impacts outcomes in liver transplantation. Although the present data are limited by the fact that they were sourced from a single institution, they suggest that morbid obesity adversely affects longterm outcomes despite providing similar short-term results. Further analysis is indicated to identify risk factors for poor outcomes in morbidly obese patients.