He co-presented Magpie from 1972 to 1980, then went on to present an out of school activity programme called Freetime. When Freetime was dropped by ITV in 1985, he helped to establish The Children's Channel, where he presented a show called Roustabout.
Since the 1980s he has produced television programmes for children, including the series Wise Up and Blunt, and has won several Children's BAFTAs. In 2007, he was awarded the Special Award Children's BAFTA for his work in television. Accepting his award he said
I am hugely proud to be receiving my Bafta award. My television career has been entirely spent in making programmes for children. There is no more important audience. ...All my programmes have been in the factual entertainment genre which is fast disappearing from children's screens because of its minority appeal. ...I hope ways will be found to support factual television for children in the future. They should always enjoy a rich and varied viewing choice.
Robertson released a couple of singles "The Tango's Over" in 1974 and "Then I Change Hands" the following year. An album also called Then I Change Hands was also released that year. None of these charted.