The present study showed the efficiency of the usage of the flax fiber as reinforcement in the wheat flour based extruded polymeric matrix. The X-ray diffraction analysis proved that the crystallinity of the lax fiber is 65% w/w and the intensity of the peaks associated to composite increases with the fiber content. The mechanical property such as stress at failure and tensile modulus increases as a function of fiber content and is maximum for the composite having a fiber loading of 20% w/w. This increase is attributed to the well dispersion of the fiber in the matrix which resulted in a good stress transfer between fiber and matrix. Scanning electron microscopy analysis also supported the above result. The strain at failure decreased significantly when the fibers were incorporated in the matrix. Thermal stability study of flax fiber showed that for the fiber the degradation occurs in two steps, first one associated with the evaporation of water followed by the second due to the degradation of the components in the fiber. Incorporation of fiber to the matrix did not
change the thermal stability of the composites. The comparative studies of the mechanical properties of the present system with other fiber reinforced starch composites proved that flax fiber can be used successfully in the wheat flour based thermoplastic films.