In this paper 31 sediment samples collected from the Danube River, Delta and Black Sea in Romania were investigated by INAA, ICP-MS and CV-AAS techniques for the quantification of 42 elements (Al, Mg, Cl, Ti, Ca, V, Mn, Na, Si, K, Sc, Cr, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Sb, Zr, Mo, Cs, Ba, La, Ce, Sm, Ta, Nd, Eu, Tb, Yb, Lu, Hf, W, Th, U, Cd, Cu, Pb and Hg) and highlighting geochemical peculiarities. Contamination and ecotoxicological risks were evaluated based on single (CF, Er) and complex (PLI, RPLI, RI) indices computed for 26 presumably contaminant elements, suggesting a pollution load in the maritime sector of the Danube and Chilia branch. Significant contribution to the RI had the elements with high toxic response factor, e.g. Hg, rare earth elements (REEs) (Lu having the highest percentage), As, Cd, U, Pb and Sb. Assessment of radiological hazard due to 238U, 232Th and 40K through the absorbed dose rate (ADR), radium equivalent activity index (Raeq), external hazard index (Hex), representative level index (IG), annual effective dose (AED) and excess lifetime cancer risk (ELCR) suggested an elevated radiation exposure of people in the Danube region compared to Black Sea littoral.