SummaryDistribution studies on U, Pu and Th have been carried out employing tri-n-butyl phosphate (TBP) as extractant to optimise the conditions for the reprocessing of spent fuel of proposed Th based Advanced Heavy Water Reactor (AHWR). Due to their high basicity and organophilicity straight chainN,N-dialkyl amides have been evaluated for their third phase formation behaviour (usually quantified by limiting organic concentration) during the extraction of thorium vis a vis TBP. Dihexyl derivatives of octanamide (DHOA) and decanamide (DHDA) were found promising in view of higher limiting organic concentration of thoriumviz.33 g and 50 g/L, respectively as compared to 26 g/L for TBP. Extraction profiles of U, Pu and Th have been obtained using these amides and compared with those of TBP. Attempts have also been made to optimise the stripping conditions using aceto-hydroxamic acid (AHA) and acetaldoxime as reductants for the partitioning of Pu from the loaded organic phase.