The Universe is in constant change. Events such as supernovae and flares from active galactic nuclei give evidence of the transient nature of the sky. Transients are typically discovered by optical surveys observing large regions of the sky at a high cadence. There is however an interest in detecting and studying the counterparts at different wavelengths in order to construct a more complete picture of the transient itself as well as from the object that gave origin to it. In this talk I will present a selection of transients we have followed-up in radio, including results on an interesting transient discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN). I will also make a quick review on what can be done with current radio facilities and how transient radio studies will revolutionize with upcoming facilities.