Ruthenium extraction with uranium and plutonium during the reprocessing of nuclear used fuel is an important element to follow because its presence leads to a decrease of the decontamination factors and causes enhanced radiolysis of the solvent. A study was carried out on the speciation of ruthenium in both aqueous and organic phases by complementary spectroscopic techniques such as FTIR and X-ray absorption spectroscopy. By providing a better understanding of the ruthenium extraction mechanism, this study will help to support the modeling of related processes.