Microplastic particles (MPPs; <5 mm) are found in skin cleansing soaps and are released into the environment via the sewage system. MPPs in the environment can sorb persistent organic pollutants (POPs) that can potentially be assimilated by organisms mistaking MPPs for food. Amphipods (Allorchestes compressa) exposed to MPPs isolated from a commercial facial cleansing soap ingested ≤45 particles per animal and evacuated them within 36 h. Amphipods were exposed to polybrominated diphenyl ether (PBDEs) congeners (BDE-28, -47, -99, -100, -153, -154, and -183) in the presence or absence of MPPs. This study has demonstrated that PBDEs derived from MPPs can be assimilated into the tissue of a marine amphipod. MPPs reduced PBDE uptake compared to controls, but they caused greater proportional uptake of higher-brominated congeners such as BDE-154 and -153 compared to BDE-28 and -47. While MPPs in the environment may lower PBDE uptake compared to unabsorbed free chemicals, our study has demonstrated they can transfer PBDEs into a marine organism. Therefore, MPPs pose a risk of contaminating aquatic food chains with the potential for increasing public exposure through dietary sources. This study has demonstrated that MPPs can act as a vector for the assimilation of POPs into marine organisms.