[en] This report is prepared at the request of the United Kingdom Nuclear Data Committee and covers the period from January to December, 1979. Nuclear data are presented by laboratory. There are contributions this year from the Harwell and Winfrith laboratories of the UKAEA, the National Physical Laboratory, the CEGB Berkeley Nuclear Laboratories, the National Radiological Protection Board, the Birmingham Radiation Centre, the University of London Reactor Centre and the University of Edinburgh. This report includes work from various collaborations between laboratories of Harwell, Dounreay, Winfrith, Windscale, Berkeley (CEGB), MOD Aldermaston, Imperial College, Glasgow University, Manchester University and Universities Reactor, Risley. Contributions on 'Chemical Nuclear Data' are gathered by the Chemical Nuclear Data Committee and grouped under that heading. (author)