Marine litter, such as plastic bags, bottles, fabrics, or fishing gear, serve as a shelter for many marine organisms that are likely to colonize artificial substrata. Such assemblages can potentially turn marine litter into vectors of alien invasive species (AIS). Here, we report the abundance and diversity of macroinvertebrates inhabiting marine litter in Peruvian beaches. Results indicate that most of the fouled items found came from land-based sources (81.5%) and Bivalvia was the most abundant class (53.5%), mainly composed of the mussel Semimytilus algosus. No significant differences were found in the abundance and diversity of macroinvertebrates (class level) among sampling sites or sources of litter. Polypropylene and low-density polyethylene items were most frequently found with fouled biota. Although none of the identified species were non-native to the coast of Peru, we discuss marine litter as a potential source of AIS in this region.