Aims: Peer status reflects the extent to which an individual is accepted by the group. Some studies have reported that low peer status in adolescence is associated with a higher risk of smoking, while others found the reverse. No studies have investigated peer status influences on adult smoking. The aim of the study was therefore to examine the relationship between adolescents' peer status and the intensity of smoking in adulthood.

Design: Prospective cohort study.

Setting: Stockholm, Sweden.

Participants: A subsample (n = 2329) of the cohort with information about adult smoking.

Measurements: Peer status was assessed sociometrically at age 13 and information on smoking was gathered through a questionnaire at age 32. Relative risks (RR) for self-reported level of smoking were calculated using multinomial logistic regression. Several family-related and individual variables were included as control variables.

Findings: Lower peer status in adolescence was associated with smoking of any intensity in adulthood. For example, the risk of heavy smoking was more than threefold (RR = 3.67) among individuals in the lowest status positions. The association with occasional smoking was abolished by controlling for factors related to adolescents' attitude to school and cognitive ability. For regular and heavy smoking the relationship was attenuated by controlling for these factors.

Conclusions: Low peer status in adolescence appears to be a risk factor for smoking in adulthood. Part of this association may be explained by adolescents' feelings towards school and cognitive ability. However, being unpopular in adolescence remains a strong risk factor for regular and heavy smoking in adulthood.