Clifton served as president of the Hospital Physicists' Association (now the Institute of Physics and Engineering in Medicine) from 1976 to 1978, and as honorary editor of " Physics in Medicine and Biology " from 1979 to 1983. He was the founding President of the European Federation of Organisations for Medical Physics (EFOMP) from 1980 to 1984, having proposed its establishment in 1978. He was a Fellow of the Institute of Physics (FInstP), and a Fellow of the Institute of Physics and Engineering in Medicine (FIPEM).