This paper explores 16--19-year-old Scottish smokers' experiences and attitudes towards smoking and their understandings of the ways in which this transitional period impacts on their smoking behaviour. The study involved 49 qualitative interviews conducted mostly in friendship pairs. Interviewees also completed a brief smoking questionnaire. The paper highlights the salience of social context in smoking initiation and maintenance, and the role of smoking across a range of social spheres. Interviewees described how transitions from school to work, further education or un/employment, impacted on their smoking. Smoking was perceived to be an important "lubricant" for social relations, and marker of an acceptable identity in familiar and new contexts which acted to reinforce and increase smoking. In contrast, smoking restrictions at home, work and/or educational settings were felt to moderate consumption. This has implications for cessation programmes for older adolescents who have been relatively ignored by tobacco control. The study also suggests that if smoke-free policies were extended to all workplaces, this would have a particular impact on smoking amongst older adolescents by hindering the transition from social to regular smoking.