ABSTRACT: In 2015, 60 million tons of ore tailings from the Fundão dam failure entered the Doce River basin and reached surrounding sandy beaches. This study evaluated the influence of sedimentology and morphology of beaches that received mining tailings on chemical element concentrations and consequent benthic community responses. We collected sediments for the physical (granulometry, heavy mineral, and calcium carbonate content) and geochemical (chemical elements) analyses and biological diversity parameters (benthic macro and meiofauna density, richness and composition) on eight beaches with different morphodynamic types. The beaches with more dissipative characteristics retained the highest contents of mud, As, Fe, Mn, V, and heavy minerals, present in the tailings. We also recorded the lowest values of density and richness of the macrofauna on these beaches, compared to more reflective beaches. These results contradict the global trend, suggesting that anthropic disturbances overlap the effects of morphodynamics in the structuring of the benthic fauna community, mainly in dissipative sandy beaches.