The extraction of Pd(II) by triphenylphosphine sulfide (Ph3PS) in benzene from nitric acid solutions has been investigated. The effect of different parameters on the extraction of palladium was studied. Based on the results, an equilibrium model is proposed. The stoichiometry of the extracted species was elucidated and found to be Pd(NO3)22Ph3PS. Possible interference with selected radionuclides that might exist in high level liquid waste was investigated and discussed.