Pollution diagnosis is difficult and costly for power grid operators. For the purpose of have an effective, low-cost and user-friendly pollution diagnosis, a Radio Frequency Identification prototype is proposed - an RFID tag for identifying and monitoring pollution in high voltage towers. For that, the following steps were performed: dielectric characterization of artificial pollution; project via simulation of RFID tags for application in metallic towers; manufacture, validation and testing of tags; sensitivity analysis of tag reach; and computational algorithm for signal treatment and subsequent identification. Pollution identification was based on variations of the Received Signal Intensity Indicator (RSSI) by the reader as a function of the amount of pollution deposited. The validation and testing of the tags were carried out in an external environment with an emulation of a de-energized high voltage tower. For all levels of deposited pollution analyzed, the average maximum reach of the signal reading, in an external environment, was 18 m. The RSSI data, obtained by reading the RFID tag, were processed and analyzed to identify the pollution deposited on the high voltage transmission towers. The results demonstrated the potential of the tags for identification and monitoring pollution levels in high voltage metal towers.