>Methodology for rehabilitation strategies evaluation aid after an accident: application and results. Post-accidental management is a matter for an optimisation process in a multicriteria context, which has to combine quantitative parameters as well as qualitative parameters. In order to fit with this problematic, a methodological work has been realised at IPSN, in the context of the Becquerel national exercise, which has simulated a Borax type accident on an experimental reactor. The methodology consists in making a systematic evaluation of indicators in order to provide intercomparating data for many rehabilitation strategies. Thus, each strategy is evaluated on the one hand in terms of radiological benefit and on the other hand, in terms of incidences such as duration of realisation, materials and human means, workers doses, amount of generated wastes. In this context, calculations highlighted the importance of counter-measures aiming at reducing the external exposure, which is the dominating exposure pathway. The counter-measures aimed at reducing the dose by ingestion lead to a reduction of specific activity are then useful mainly in regard to the limits of commercialisation. This work is a first and useful contribution to the clarification of the post-accidental rehabilitation problem. It has also put the light on three important needs: formalisation of counter-measures and gathering into a data base, adaptation of calculation tools to make their use easier, and improvement of the knowledge of the operational considerations for the interventions.