Despite the presence of various nerve coaptation materials and techniques, achievement of the functional nerve regeneration is still inadequate. This study was aimed to compare the effectiveness of conduit composed of collagen biomatrix and omentum graft on peripheral nerve regeneration. Thirty-five male Wistar rats were divided into four groups. In the control group, the right sciatic nerve was skeletonized from the sciatic notch till the point of bifurcation. In the primary epineural repair group, the nerve was transected 1 cm proximal to the bifurcation with a sharp pair of micro scissors and then repaired with four epineural sutures. In the collagen biomatrix group, the epineural repaired nerve was wrapped with collagen biomatrix. In the collagen group, the epineural repaired nerve was wrapped with the nonpediculated omentum. Assessment of the nerve regeneration was based on functional (Walking Track Analysis, Electrophysiological Measurements), histological, and morphometric criteria. Light and electron microscopic examinations showed that collagen-biomatrix-wrapped specimens have the best regeneration. The electrophysiological study confirmed the recovery of electrical activity in the regenerated axons. © 2009 Springer-Verlag.