This note continues an annual series on mortality rates in Great Britain; the previous note in the series appeared in J.I.A. 107, 529 and dealt with mortality in 1978. Tables 1 and 2 below show central death-rates for Great Britain for the years from 1966 to 1979 and Tables 3 and 4 show the ratios of these rates to the corresponding average rates for the three years 1970–72, which have been taken as a standard. Death-rates in this form for the years from 1961 to 1978 have been published in earlier notes in this series. The rates for 1979 have been calculated using the deaths recorded as occurring in Great Britain in 1979 and the ‘home’ population at 30 June 1979, i.e. the number of people actually in the country at the time, as estimated by the Registrars General of England and Wales and of Scotland.