The value of employing electronic surveillance in the investigation of some forms of serious crime is unquestionable. It allows the gathering of information unattainable through other means. This document aims to assist legislative drafters, policymakers, legal practitioners, law enforcement and other investigative authorities involved in or considering electronic evidence gathering. It hopes to provide a comprehensive outline of measures and options which may be considered for incorporation into respective legal systems and operational procedures subject to the particular social, political and economic circumstances of their countries.