Active smoking is an increasing problem amongst U.K. teenagers. The smoking habits of a cohort of 14-16-year-olds were determined and the association between regular active smoking and domestic and social factors investigated. Current smoking habits of a cohort of 2289 14-16-year-olds were assessed using a simple postal questionnaire. Data concerning potential factors associated with active smoking were collected from questionnaire completed by parents. Nine hundred and sixty-nine (44.8%) children admitted to having smoked at some time, with 562 (30.0%) having smoked in the previous 12 months. Three hundred and six (14.1%) children were regular smokers and 158 (51.6% of regular smokers, 7.3% of total cohort) smoked daily. Age, number of other children in the household, parental smoking, smoking sibling(s) and living in a single parent household were all independently associated with regular smoking. Regular smoking was a significant problem amongst this cohort of teenagers. Living with other smokers, age, household size and living with one parent all predicted a regular smoking habit.