A resistance-grounded distribution system has a critical element that is often forgotten — the neutral-grounding resistor (NGR). Because NGR's are subject to failures [1] related to thermal overload, lightning, storms, extended service life, manufacturing faults, vibration, corrosion, and improper specification or installation, the proper monitoring of NGR health is important as all other protections to preserve distribution system in safe state. With several studies and field measurements we managed to establish a correlation between voltage and current on NGR during normal operation (different states of load on transformer or without load) of resistance-grounded distribution system and again on same states with faulty NGR. NGR failure detecting algorithm [2] is divided in several stages. First stage continuously monitors minimal current that always flows through NGR. Second stage calculates resistance from current and voltage through NGR and reports deviations from normal resistance. Third stage monitors higher currents through NGR and indicate that NGR could be partially damaged. This functional algorithm with specially developed hardware combines an advanced monitoring of NGR failure detection that could improve distribution system safe operation. During two years operation supervision of implemented detections on several NGR's in distribution company of Elektro Primorska d.d. and field testing we manage to confirm proper operation of NGR failure detection. With some improvements of algorithm also verification results [3] are presented in this paper.