This study examined whether the severity of posthepatectomy liver failure (PLF) affected the long-term postoperative liver recovery of patients with hepatocellular carcinoma (HCC). We performed a retrospective cohort study of 395 HCC patients who underwent hepatectomy from 2004 to 2012 at the Kyoto University Hospital. The severity of PLF between postoperative days 5 and 10 was categorized according to the International Study Group of Liver Surgery criteria. We compared the Child-Pugh (C-P) score, platelet count (PLT), and the ratio of future remnant liver volume (FRLV) to the total liver volume (%RLV) at 3, 6, and 12 months after hepatectomy in the non-PLF, grade A, and grade B groups. The non-PLF, grade A, and grade B groups contained 272, 63, and 56 patients, respectively. The C-P score in the grade A group recovered from 5.37 points before hepatectomy to 5.38 points at 12 months after hepatectomy. The C-P score in the grade B group increased from 5.51 to 6.81 points at 3 months and was significantly higher (6.00 points) at 12 months than in the non-PLF group (5.47 points). The PLT significantly decreased at 12 months in the grade B group compared with the non-PLF group. The %RLV at 12 months in the non-PLF, grade A, and grade B groups were 84, 83, and 78 %, respectively. The remnant liver hypertrophy in the grade B group was significantly slower than that in the non-PLF group. PLF severity affects long-term liver function recovery and remnant liver hypertrophy after hepatectomy.