BACKGROUND Liver transplantation (LT) in infants is a challenging procedure. This study was designed to identify risk factors of 30-day mortality of infant LT recipients. MATERIAL AND METHODS A total of 101 infants treated between May 1997 and March 2015 were assigned to one of two groups, a deceased infant group (n=9) or a live infant group (n=92), according to their mortality status at 30 days after LT. RESULTS Patient characteristics of height, weight, preoperative total bilirubin, creatinine clearance, primary diagnosis, and graft-to-recipient weight ratio (GRWR) were significantly different between the two groups. In a binary logistic regression model for multivariate analysis, independent predictors of postoperative mortality in infants after LT were hospitalization in the intensive care unit before LT, reoperation within 30 days of the first operation, and high GRWR (>4). CONCLUSIONS Postoperative mortality of infants following LT showed significant correlations with recipient preoperative and postoperative conditions and also with graft size mismatch. Regarding GRWR, our data indicated that relatively large grafts given to infant recipients often lead to graft failure or primary nonfunction during the postoperative stage.