Partial discharge (PD) testing of cable systems can benefit from the use of time synchronized PD detectors since (a) location and identification of PD phenomena is easier, (b) the logistics are greatly simplified as the voltage reference signal must be provided to one detector only (thus exploiting, e.g., instrument transformers at cable terminals). This paper will show how measurements can be synchronized to the global positioning system and how the information provided by synchronized detectors can be exploited. A practical case of measurements on a HV cable will be presented to show the effectiveness of the time synchronized measurements.