The study of the hematopoietic system raises some fundamental issues about the regulation mechanisms that control the overall production of terminally differentiated blood cells. To address such issues, it is our view that both inter- and intra- cellular dynamics have to be considered. The macro-level self-organisation of the hematopoietic system emerges from the local micro-level interactions of its components. Following such premises, in this paper we propose a novel approach for modelling hematopoietic stem cells behaviour based on multi-agent systems. The adoption of this paradigm allows to take into account the aspects suggested above, explicitly modelling cell internal behaviour, the environment where they are situated and the interaction between the system entities.