In this work, quantitative crystalline phase analysis of 316L stainless steel from wire to fiber using a multi-pass cold drawing process was studied using the Rietveld whole XRD profile fitting technique. The different diameters of the fibers: 179, 112, 75, 50, 34, 20, and 8 mu m, were produced from an as-received wire with a diameter of 190 mu m. The crystalline phases were identified using MDI Jade 5.0 software. The volume fractions of crystalline phases were estimated using a Materials Analysis Using Diffraction software. XRD analysis revealed that the crystal structure of as-received wire is essentially a gamma-austenite crystalline phase. The phase transformation occurred during the 316L stainless steel from wire to fiber. Three crystalline phases such as gamma-austenite, alpha'-martensite, and sigma phase of the fine fiber were observed. A cold drawing accelerates the sigma phase precipitates, particularly during the heat treatment of the fiber. (C) 2010 Elsevier B.V. All rights reserved.