Substituted phenylamine antioxidants (SPAs) are additives in a variety of commercial polymers (e.g., lubricants, plastics, etc.). Based on their physicochemical properties, if SPAs were to enter an aquatic system, they would likely partition into sediment and have the capacity to bioaccumulate in biota. This study investigated the potential of four sediment-associated SPAs, diphenylamine (DPA), N-phenyl-1-naphthalene (PNA), N-(1,3-dimethylbutyl)-N’-phenyl-1,4-phenylenediamine (DPPDA), and 4,4’-methylene-bis[N-sec-butylaniline] (MBA) to accumulate in the tissues of freshwater mussels (Lampsilis siliquoidea) and oligochaete worms (Tubifex tubifex). Mussels and worms were exposed to sediment spiked with individual SPAs for 28 d. The concentration of SPAs was measured in the gill, gonad, and remaining viscera of the mussels and entire body of the worms. The majority of biota-sediment accumulation factors (28-d BSAFs) for the different tissues of mussels were