In this work the quenching and partitioning (Q&P) treatment is applied to AISI 9260 steel combining different quenching temperatures (QT), and partitioning times and temperatures in order to evaluate mechanical properties (e.g. ultimate tensile strength, elongatin, toughness, and their combination). AISI 9260 steel, besides having the advantage of a lower cost than most of the low alloy steels, can achieve high retained austenite (RA) fraction levels through the application of the Q&P treatment thanks to its few alloying elements, mainly silicon. The importance of RA lies in its ability to improve ductility and toughness; in this work, RA is determined via X-ray diffraction analysis (XRD) and the mechanical properties are assessed through conventional tensile test and, fracture toughness test (FT)-FT being seldom reported in several Q&P studies. The results of the present work suggest that the Q&P treatment applied to AISI 9260 steel could increase its industrial use by virtue of a good combination of strength, ductility and toughness.