This Safety Guide provides recommendations on the operating organization and on personnel for research reactors to meet the relevant requirements of IAEA Safety Standards Series No. SSR-3, Safety of Research Reactors. It covers the typical operating organization for research reactor facilities; the recruitment process and qualification in terms of education, training and experience; programmes for initial and continuing training; the authorization process for those individuals having an immediate bearing on safety; and the processes for their requalification and reauthorization. This Safety Guide is a revision of IAEA Safety Standards Series No. NS-G-4.5, which it supersedes.