The aim of this work is to nondestructively characterize the dual phase steels using the Magnetic Barkhausen Noise (MBN) method. By quenching of AISI 8620 steel specimens having two different starting microstructures, from various intercritical annealing temperatures (ICAT) in the ferrite-austenite region, the microstructures consisting of different volume fractions of martensite with morphological variations have been obtained. The microstructures were first conventionally characterized by metallographical investigations and hardness tests. Then, the MBN measurements were performed using a mu SCAN commercial system. Good correlations between the martensite volume fraction, hardness and MBN emission have been obtained. MBN signal height clearly decreased as the ICAT, therefore the volume fraction of martensite increased. The effect of the initial microstructure prior to intercritical annealing has also been differentiated by the MBN measurements. It has been concluded that MBN method can be used as a useful tool for nondestructive characterization of dual phase steels.