After a short review of the history and an introduction into the background of standardization in the field of mental work-load an overview over the ISO 10 075 series of standards on ergonomic principles related to mental work-load is given. The review also presents relationships of these standards with some other ergonomic standards and some of the problems associated with standardization in the field of mental work-load. The stress-strain model, the concepts and the terminology used in ISO 10 075 are presented in the overview, together with the basic ideas and the frame of reference of the design guidelines provided by ISO 10 075-2. An outline of the state of discussion and possible developments of a working draft for ISO 10 075-3 on diagnostic methods concludes the presentation of the international standards on mental work-load.