networks Oscar Ornago*, Riccardo Chiumeo*, Luciano Garbero*, Ignazio Mastandrea* Adalberto Porrino** 12th International Conference on Harmonics and Quality of Power (ICHQP) Cascais (Portugal), 1-5 Ottobre 2006 * CESI RICERCA ** CONSULENTE In response to the increased request for customers protection and quality improvements, an innovative system for wide-ranging power quality monitoring of Medium Voltage distribution networks was implemented in Italy. The main aim of the monitoring system is to provide a baseline of knowledge on the actual quality level in Italy and to enable the relevant regulatory actions in the interest of consumers. The monitoring system consists of 600 measurement units of Voltage Quality parameters and of a central system for data collection and storage. Privileged and public users can gain access and examine the results of the ongoing monitoring campaign through a web system. The paper illustrates a) the criteria adopted to choose the points to be monitored, b) the system architecture, and c) the technical characteristics of the measurement units and of the central system for data collection and storage. Finally the main features of the web system as well as some examples of data reporting are describe