The selection of optimum transmission cable systems with respect to technical, economical andenvironmental considerations is usually a complex decision. This guide facilitates that selectionprocess for underground transmission cables.This guide contains two main parts. The first part describes the methodology of the selectionprocess, consisting of three different steps including the assessment of conditions and the selectionof a cable type. The second part of the document provides relevant information to help the utilitymake the right decision for their specific circumstances. The information deals with a variety ofimportant issues: review of cable types, manufacturers, operating experience, diagnostic methods,environmental considerations and costs. Furthermore, information is given on the steps to followafter the selection process: the preliminary design phase and the tendering process. In some specialcases the selection process of the utility may result in two candidates, in which situation the decisionabout the final design will be made after the tendering.Keywords:Cable, Transmission, Design, Engineering.