The mechanical behavior of micro-composites Duplex Stainless steels (DSS) produced by Accumulative re-Bundling and Drawing (ABD) has been investigated. We evidenced a systematic increase in the yield strength, as a function of the manufacturing step, independently from the phases' volume fraction. A simple rule of mixture (ROM) successfully predicted the first generation of composites presenting a simple microstructure. However, a modified ROM taking into account the contribution of each component and its grain size could not predict the mechanical response of the composites of higher generation. An in-depth analysis is conducted to investigate the microstructure-mechanical behavior relationship and to rationalize the resultant mechanical behavior from that of each constitutive phase. For this purpose, in-situ synchrotron High Energy X-ray Diffraction measurements during uniaxial tensile experiments have been carried out to calculate the strain partitioning within each phase of the composites.