The mediating effect of job characteristics in the socioeconomic status (SES)-health relationship has not been well studied in the young adult population. The early health trajectory is important to study since the health trajectories of young people shape their health in later years. The purpose of this study was to determine whether the education defined SES-health relationship is mediated through job characteristics, controlling for healthy lifestyle factors in young adults. We hypothesize that accounting for differences in job quality would reduce the education-health gradient. Using a sample of 10,215 Canadian workers aged 20-29 years, we used multivariable logistic regressions to examine the associations of sociodemographic, work, and lifestyle factors with two health outcomes, self-perceived health and work-related injury. The key findings indicate that job characteristics partly explain the education gradient observed in work-related injuries, and to a lesser extent in self-perceived health for working young adults. Our results show that increased physical exertion and working in sales and service or manual occupations were job characteristics which were independently associated with work-related injuries, while low work-related social support and irregular shift work were associated with poor self-perceived health. Lifestyle factors have a greater association with the education-self-perceived health relationship. This pattern of findings suggests that work factors related to education have a more specific effect on occupational health early in the health trajectory. These findings have potential practical implications since policies to reduce poor health must be targeted at appropriate age groups, as workers need to be healthy in their younger years in order to stay in the workforce as they age.