Benthic communities contain some of the most threatened organisms in aquatic habitats due to different anthropogenic pressures. The high abundance of microplastics (MPs) in sediments will continue to increase in the future, further increasing the probability of interactions between macroinvertebrates and MPs. In the present study, a benthic community in a relatively pristine shallow pond was exposed either to an environmentally relevant high concentration of an MP mixture of 80 g m-2 in the sediment, or a control sediment, without the addition of MPs. The mixture of MPs contained irregular shaped polyethylene (PE), polyvinyl-chloride (PVC), and polyamide (PA) in a ratio of 50%: 25%: 25%, respectively. The in situ experiment lasted for 100 days. The total number of taxa that colonized the microcosms was 22 (17 in the control, 18 in the MP treatment), and the colonization was not affected by the treatment. The most dominant group within the macroinvertebrate community was the dipteran family Chironomidae, both in the control and the MP treatment. No significant differences in the abundance and biomass at a community level were recorded between the groups by PERMANOVA ((F=0.993; p=0.456 and F=0.344; p=0.797, respectively). The mixture of MPs did not influence the abundance or biomass of the functional feeding groups (F=1.810; p=0.137 and F=0.377; p=0.736, respectively). The species richness (S), species abundance (N), species biomass (B), Shannon’s diversity index (H) and Simpson’s index of diversity (D) showed no statistically significant differences between the control and treatment groups. Czekanowski’s quantitative similarity index indicated that 84% of the community remained unaffected after MPs exposure.