Wireless Sensor Networks (WSNs) are arising from the pro- liferation of Micro-Electro-Mechanical Systems (MEMS) tech- nology as an important new area in wireless technology. They are composed of tiny devices which monitor physi- cal or environmental conditions such as temperature, pres- sure, motion or pollutants, etc. Moreover, the accuracy of individual sensor node readings is decisive in WSN ap- plications. Hence, detecting nodes with faulty sensors can strictly influence the network performance and extend the network lifetime. In this paper, we propose a new approach for faulty sensor node detection in WSNs based on Copula theory. The obtained experimental results on real datasets collected from real sensor networks show the effectiveness of our approach.