In this paper, we present the results of a hybrid fiberoptic and RF-sensing technology for monitoring partial discharges on hydrogenerators, which can also be used for several other applications. The main advantages of the proposed system are passivity, flexibility, nonintrusive, inherently dielectric, and human and equipment risk-free. We describe the performance evaluation of the sensing system in laboratory and in field trial installed in a hydroelectric power station located in north of Brazil.