Recently, there has been increasing need and interest in adopting wireless sensors to structural health monitoring (SHM) applications. Smart wireless sensors have been considered as an alternative tool for convenient and economical realization of SHM system. The wireless sensors can provide rich information which SHM algorithms can utilize to detect, locate, and assess structural damage caused by progressive deterioration under operational loadings and severe loading events. Many applications of wireless technologies to real structures have been made for on-line wireless SHM of in-service civil infrastructures. This paper presents several hardware/software issues and example applications of smart wireless sensing technologies. The first example is smart wireless sensor network, which is applied to a cable stayed bridge. The second one is a multifunctional wireless impedance sensor node, which is fabricated and applied to a real steel bridge. The last one is an innovative wireless system for guided wave excitation and sensing based on laser and optoelectronic technologies, which has been experimentally demonstrated.