Aim of this study is the correlation among magnetic properties, tensile deformation and microstructure of the duplex stainless steel 2205. This correlation is achieved by the magnetic ferrite phase of the two phase microstructure. The amount of Barkhausen noise for a given material is linked with the amount of impurities, crystal dislocations, etc. and can be a good indication of mechanical properties of the material. Specimens of the alloy DSS2205 were tested under tensile deformation in different percentages and the magnetic measurements were taken online, during the tensile deformation. The measurements of the parameters of BHN combined with the percentages of the deformations and their graphic plot showed an exponential relationship. Microstructure studied with SEM technique. Macro hardness also measured and its measurements compared with those of BHN. The resultant plots showed a linear proportion among them.