Wireless Sensor Networks (WSNs) present a new generation of real-time embedded systems for a wide variety of applications. However, WSNs have limited computation, energy and memory resources. One of the approaches to minimize the energy consumption is to allow only some nodes in a cluster of sensor nodes called cluster-heads to communicate with the base station. Appropriate cluster-head election can drastically reduce the energy consumption and enhance the lifetime of the network. In this paper, a fuzzy logic approach to cluster-head election is proposed based on three descriptors-energy, concentration and centrality.