Human resources are considered as one of the important intangible resources of company composed mainly of employees' knowledge, skills and attitudes. When human capital is scarce, precious and difficult to imitate, it can be a source of sustainable competitive advantage. Internal Relationship Marketing (IRM) acts in this sense. It is considered as a process of creating, developing and maintaining sustainable relationships between the company and its employees. In this context, and through an analysis of the existing literature in this field, we will try to study the effects of IRM on the employee job performance. The main results of this work are that the IRM, through its relational determinants namely: communication, organizational trust, organizational commitment and job satisfaction, help improve employee job performance and more precisely task performance and contextual performance. This study wraps up by a proposal of a conceptual model, linking the different components of our research.