Because different studies suggest that psychological harassment represents a great threat to most workers, it has received considerable and growing interest across the world and has emerged as a new field of study in Europe, Australia, South Africa and the USA. In spite of these studies, bullying still appears as a complex phenomenon. This paper summarises the literature and proposes a specific model of psychological harassment process. This model presents psychological harassment like a four phase's process and improves the understanding of this pernicious workplace phenomenon. Thus, it appears as a very costly phenomenon which harms the health of the victim and the competitiveness of the firm. Therefore, the paper concludes HR managers should combat psychological harassment in organisations.