While obesity is associated with liver cancer in studies from western societies, the paucity of data from Asia limits insights into its aetiological role in this population. We examined the relationship between body mass index (BMI) and liver cancer mortality using data from the Asia Pacific Cohort Studies Collaboration. In 309,203 Asian study members, 4 years of follow-up gave rise to 11,135 deaths from all causes, 420 of which were ascribed to liver cancer. BMI, whether categorised according to current guidelines for Asian groups or World Health Organisation recommendations, was not associated with liver cancer in any of our analyses.