High resolution acoustic data and several sediment gravity cores taken in the region of Ob and Yeneisei estuaries allow us to balance the Holocene sediment budget of both rivers and reconstruct their evolutionary history. The physical properties and core descriptions were used for ground truthing.The Ob and Yenisei estuaries act as major terrigeneous supplied sediment sinks in Holocene times. A total of 14 * 1010 tons and 9 * 1010 tons of fine-grained sediments, respectively have accumulated in the Holocene. These numbers lie in the same order of magnitude as the extrapolated modern river run off for the last 8000 years. High sediment thickness could be traced up to 73°30`N of latitude which is decreasing rapidly further to the north. Sedimentation is dominated by the first occurrence of sea-water. One high resolution CHIRP sonar profile exhibits a fluvial dominated depositional environment for the early Holocene displaying lateral accretion as point bars and vertical accreted overbank deposits such as levee structures. In terms of facies classification it represents a fine grained meandering river environment. The whole succession represents a transgressive system tract.