The human dimension of sustainability, defined by the ability of employees to thrive and to engage in the workplace, has often been given less attention compared to economic and environmental dimensions. A satisfied and engaged workforce is considered to be a cornerstone of sustaining a competitive advantage and the sustainability of the organization (long-run success). This paper analyzes the link between job satisfaction, work engagement and sustainability of services organizations in Romania, through a quantitative research among 231 employees. Using the role theory, we measured employees' perceptions of conflict and ambiguity over stress at work and the impact it has on job satisfaction and work engagement. To test the conceptual framework, a structural equation modeling (SEM) technique was used to empirically explore the research model. The way in which job satisfaction influences business sustainability could be described both directly and indirectly by the mediating power of other factors. In fact, the indirect path, in our case by the partially mediation of work engagement, potentiate and explains more the relationships between all investigated factors.