This article aims to explore the ways in which preadolescents associate smoking with transitions to adulthood, in the context of sociological theories of childhood, using data from the Liverpool Longitudinal Study of Smoking. The research found that at age 9 many of the cohort argued that smoking was more acceptable for adults because they had bigger bodies than children. Some children also suggested that smoking was appropriate for adults because adults were competent to make important decisions and to balance risks. By age 11, when several of the cohort had actually tried smoking, children's views about the risks smoking posed to their bodies had altered, and many children were aware of smoking-related disease among adults. The cohort also suggested that some children might take up smoking to demonstrate that they are "grown up" too. In the UK, legal restrictions on the age of tobacco purchase are reinforced by social norms that construct smoking as an activity that is only suitable for adults. The goal of legal restrictions that ban the sale of cigarettes to children is to protect their health. The unintended outcome, however, is that for many young people smoking is a way of demonstrating maturity and adult status.