As part of research in the lower reaches of the Northern Dvina River during the summer periods of 2023-2025, the results of an analysis of quantitative (abundance and biomass) and qualitative (taxonomic composition) indicators of zoobenthos, as well as the content of petroleum products in bottom sediments, are presented. A total of 28 species and supraspecific taxa of benthic invertebrates were identified in the taxonomic composition of zoobenthos during the study periods. Representatives of oligochaetes, chironomid larvae, bivalves, and gastropods had the largest shares in abundance and biomass. Over the study periods and among all studied sections of the Northern Dvina River, the maximum values of quantitative indicators were recorded within the city of Novodvinsk in the summer of 2023 due to the large number of bivalves. At the railway bridge, the maximum quantitative values over three years were noted in the summer of 2024, in the area of the village of Gnevashevo and in the estuary coastal area - in the summer of 2023, in the village of Ust-Pinega - in the summer of 2025. Maximum concentrations of petroleum products in bottom sediments were observed in 2024 (from 7.54 to 28.29 mg/kg), with peak values in the coastal estuary area, and in 2025 (from 13.02 to 25.27 mg/kg) in the railway bridge area. As the content of oil products in bottom sediments increases, there is a small, but still a decrease in the quantitative parameters of zoobenthos.