The aim of this study is to investigate the effect of martensite volume fraction (MVF) on the erosive wear rate of dual-phase (DP) steels. For this experimental study, low carbon and low alloyed AISI 8620 steel was used. As received the cylindrical bars of this steel were homogenised and normalised before DP heat treatment. To determine the effect of MVF on the erosive wear rate 7 critical temperatures were selected between A(C1) and A(C3). 2 mm thick disks of AISI 8620 were intercritically annealed at these 7 different temperatures for 20 min and they were quenched in a brine solution at -10 degrees C. MVFs of polished and etched specimens of DP AISI 8620 steel were explored by the help of an image analyse program : Image ProPlus (C) 5.0. On the other hand, erosive wear tests were carried out at a constant impact angle of 90 degrees and at a constant impact velocity of 30 m/s for time periods of 240 s. It was observed that erosive wear rate decreases by increasing intercritical annealing temperature (ICAT) and MVF.