Due to limitations in the accuracy of clinical MRI, adults with traumatic brachial plexus injuries (BPI) undergo major exploratory surgery to define their injury. Early exploration and reconstruction restores limb function and improves quality of life. Diffusion tensor imaging (DTI) tractography offers the potential to replace exploratory surgery by assessing the continuity of the roots of the brachial plexus. Twenty healthy adults were used for sequence development on a 3 Tesla system and the protocol validated on 12 patients with known patterns of BPI. DTI reliably reconstructs the normal and injured brachial plexus with high fidelity and superior diagnostic accuracy.