Aims and Background: Advances in rhizosphere research substantially contribute to the risk assessment of trace element phytoavailability in contaminated soils. Conceptually, there is increasing evidence that standardised chemical methods usually performed on bulk soil are not per se able to take into account root-induced chemical changes occurring in the rhizosphere. Methodologically, the development of the root mat technique with a physical separation between roots and soil enables an easy, fast and clean recovery of roots that fails in current standardised biotests. This communication introduces the approach and the major outputs of the NormaRHIZO project (2010-2012) aiming at developing up to ISO standardisation a plant-based biotest originated from rhizosphere research, the RHIZOtest, to assess trace element phytoavailability. Results: At mid-project, the major achievements include (i) the development of a routine RHIZOtest procedure and (ii) the selection of three target plant species exhibiting contrasting behaviour among the ten crop species tested. Additional investigations are currently performed to refine the scope of the RHIZOtest over a broad range of soil properties and in comparison with chemical methods. Conclusion: Finally, the RHIZOtest development toward its standardisation is an example of how the outputs of rhizosphere research can be raised to an operational level.