Wireless sensor network (WSN) has emerged as an important tool for structural health monitoring. This paper presents an evaluation of a WSN protocol, which consists of 4 wireless sensor nodes for structural monitoring applications. A series of laboratory experiments were conducted by installing the wireless sensor nodes on a model building. The results were compared with traditional piezoelectric accelerometers. The results showed that the recorded acceleration time history by wireless sensors matches very well with those by traditional wireless accelerometers. The experience of deploying the WSN on a four span bridge was described. The wireless sensors were found to have failed to work properly due to communication interference. This provided lessons for applying wireless sensor network under field conditions. Most of the problems of this WSN were found to be related to the middleware of the WSN, namely signal communication, working status control, data transferring rate, time synchronization of sensor nodes and the interference of existing networks. This paper also highlights the limitations of existing sensor notes, with the intention to help overcome the obstacles of using WSN. The paper provided recommendations for the proper use of a wireless sensor network in engineering projects. While wireless sensors performed very well under good communication conditions, improvements in sensor hardware and software are needed to improve the reliability of data communication.