The rupture of the C??rrego do Feij??o Dam close to Brumadinho municipality is one of the recent and most devastating environmental disaster in Brazil. This study aims to report the results of metal determinations and acute toxicity assays of mining tailing samples collected 5 days after the dam rupture. Concentrations of As, Cu and Ni in site 1 (close to the dam); concentrations of Cu, Zn and Pb in site 2 (Solo Sagrado) and As, Cd and Cr in the three replicates of site 3 (Mario Campos municipality) were higher than TEL reference value. The Cd concentration in of site 1, and As, Cd and Ni concentrations in of site 2 were higher than the PEL reference value, indicating effective effects of these metals to biota. Corroborating with previous studies, the Uranium contamination was detected close to Solo Sagrado. However, the evaluation of radionuclides came to the absence of relevant radioactivity. Regarding the ecotoxicological assays, survivor percentages of Daphnia similis were lower than the lab control in sites 2 and 3. Thus, results support concerns regarding environmental recovery, which can take years to occur. Monitoring of biota, abiotic and physical-chemical parameters should be performed continually.Coordena????o de Aperfei??oamento de Pessoal de N??vel Superior (CAPES)CAPES: 88882.315518/2019-01