Applying Wireless sensor networks (WSNs) in structural health monitoring (SHM) systems has received significant interest from research communities in recent years. While incorporating wireless technology in monitoring systems has provided considerable improvements, new approaches are still needed to address existing challenges in their application. A major challenge in application of WSNs in SHM is the limited power resources of wireless sensors and the latency in the data processing due to the low communication bandwidth. The performance of the networks on both of these factors can be improved through the use of an iterative modal identification algorithm, called IMID. This algorithm uses the local processing capability of wireless sensors and provides a substantial reduction in required communication for identification of system’s modal properties. The iterative approach is such that, starting from an initial estimate of the system’s parameter, all of the nodes of the network use their local measurement and update the estimated modal parameters one-by-one until the convergence of results happens. In this manner, the system’s parameters are the only data that need to be transmitted through the network for updating. This approach results in the significant reduction in the total volume of communication. This paper presents the application of the IMID in modal identification of a 3-D steel truss structure. The results are discussed and the performance of the algorithm is evaluated.