Only a few previously published studies have investigated the co-occurrence and clustering of health-risk behaviors in people with different socio-economic trajectories from childhood to adulthood. This study was based on data collected through the Stockholm County Council's public health surveys. We selected the 24,241 participants aged 30 to 65 years, who responded to a postal questionnaire in 2010. Information on parents' and participants' educational levels was used for classification of four socio-economic trajectories, from childhood to adulthood: the ‘stable high’, the ‘upwardly mobile’, the ‘downwardly mobile’, and the ‘stable low’. Information on daily smoking, risky drinking, physical inactivity, and poor diet was used for assessment of health-risk behaviors: their prevalence, co-occurrence, and clustering. We found all health-risk behaviors to be more prevalent among women and men with a downwardly mobile or stable low socio-economic trajectory. Accordingly, having three or four co-occurring health-risk behaviors were much more likely (up to 4 times, in terms of odds ratios) in these groups as compared to the women and men with an upwardly mobile or a stable high socio-economic trajectory. However, clustering of the health-risk behaviors was not found to be stronger in those with a downwardly mobile or stable low socio-economic trajectory. Thus, the fact that women and men with a disadvantageous socio-economic career were found to have co-occurring health-risk behaviors more often than people with an advantageous socio-economic career seemed to be generated by differences in prevalence of the health-risk behaviors, not by differences in clustering of the behaviors.