Abstract : Wireless Sensor Network (WSN) has become closer to our day-to-day life and has boundless future potentials. As the demand and popularity increases, the responsibility to make the network more reliable also increases. These lead to the development of fault-tolerant WSN. Usually, WSNs are used for monitoring or controlling an unattended or hazardous area, which needs a highly reliable fault-tolerant system. A fault-tolerant system will continue its service even in the presence of a fault and has to detect the faults and recover the system from the failure. Thus, a fault-tolerant system has a lot of requirements. The focus of this paper is on exploring various fault-tolerant techniques for WSN. This paper examines the exigency of developing a fault-tolerant wireless sensor network and elucidates the mode of attaining a fault-tolerant WSN. © 2019, Springer Nature Singapore Pte Ltd.