Gravitational astronomy provides a new, powerful tool to investigate the previously unexplored strong-field regime of gravity, in which compact bodies evolve and emits gravitational waves in a highly dynamical and non-linear evolution. A cornerstone of such research program is represented by the opportunity to test the nature of the most compact astrophysical objects known and to explore the possibility that compact sources other than black holes and neutron stars may exist in the Universe, leaving detectable signatures in the emitted gravitational signals. Within the variety of proposals, boson stars stand among the best motivated models, and can be interpreted as self-gravitating condensates of astronomical size, composed of either scalar or vector massive fields. During the talk I will discuss some of their main features and how these can be used to construct waveform templates in order to search for these objects and infer constraints on their fundamental properties with future observations by ground and space-based interferometers.