Background: Several studies show an association of childhood socio-economic status (SES) with
            adult smoking; however, mostly paternal occupation only or aggregated indices are
            used. We investigated the role of different childhood SES indicators for adult smoking
            behaviour. Methods: Cross-sectional data of the CARLA Study (Cardiovascular disease, Living and Ageing
            in Halle) including 1779 men and women aged 45–83 were analysed. The four indicators
            of childhood SES were school education and occupational position of each parent. We
            used logistic regression models to calculate sex-stratified age-adjusted odds ratios
            (OR) with 95% confidence intervals (CI) of current smoking by the individual childhood
            SES indicators, the highest SES category being the reference. Results: Twenty-three percent of men and 14.4% of women were current smokers. In men, school
            education of both parents was statistically significantly associated with smoking.
            Men with unknown paternal education had the highest risk (OR 2.3, CI 1.1–4.6). With
            increasing paternal education, ORs decreased. For men whose mother had a low or medium
            education, ORs were lower compared to those with highly educated mothers. After adjustment
            for the three other childhood SES indicators and adult SES, social differences partly
            increased. Small differences were observed by father's occupation, while men with
            a blue collar mother had a nearly 2fold risk of being a smoker than men with white
            collar mothers. In women, none of the childhood SES indicators was statistically significantly
            associated with adult smoking, although there was a strong social gradient for maternal
            education. Women with unknown maternal education had a 2.4fold risk of smoking; the
            lowest risk was found in women whose parent was self-employed or farmer. Conclusions: For men, parental education was associated with adult smoking; however, different
            patterns emerged for father's and mother's education. No statistically significant
            relation of childhood socio-economic indicators with smoking was observed in women.