Radio signatures of lightning discharges on Saturn and Uranus have been discovered by the Voyager spacecraft in 1980 and 1986, respectively. These impulsive radio bursts are caused by planetary lightning activity. Additional measurements and continuous monitoring only became possible in 2004, when the Cassini spacecraft approached Saturn. Since 2006, ground-based observations are available as a complementary source of information. Using a new broadband receiver at UTR2 (Ukraine), Saturn lightning has been observed over the whole spectral range of the instrument (10-30 MHz). For the first time, this allows to study the instantaneous spectrum of the discharge, and the temporal fine structure of the emission can be studied with a temporal resolution surpassing that of regular satellite observations. Additional observations were performed with the WSRT and with LOFAR. We present recent and ongoing observations, describe the methods and techniques used and discuss the potential of new-generation radio telescopes for the detection of lightning emission from different solar system planets.