The current study focused on job satisfaction and job performance, as well as on their predictors in a privatized organization. We tested a model in which job satisfaction, consistent with social cognitive theory, is related to self-efficacy and perceptions of social context (i.e., colleagues, immediate supervisor, top management); job satisfaction, in turn, predicts job performance along with organizational tenure. White collars (N = 1172) from the staff and line functions of an Italian privatized organization were administered a self-report questionnaire matched with their job performance as rated by supervisors (six months later). Structural equation modelling supported the hypothesized relationships among variables. We found that: (a) self-efficacy was related to the three components of perceptions of social context; (b) perceptions of social context mediated the relationship between self-efficacy and job satisfaction; (c) job performance was positively predicted by job satisfaction; and (d) finally, the relationship between organizational tenure and job performance became progressively negative as organizational tenure increases, indicating a misfit between the person and the organization for employees hired before the privatization. Our findings suggest interventions directed at enhancing employees’ self-efficacy in mastering job tasks under unstable conditions, at supporting supervisors in managing their coworkers, and at improving the fit between higher-tenured employees and the organization.