This publication is primarily addressed to members of the technical or administrative staffs of government services or assistance to development agencies working in field projects related to prevention of grain losses. It is a manual of basic information on post-harvest operations concerned with the principal foodstuffs of the developing countries: rice, maize, sorghum, beans, groundnut and sunflowers. This publication should help to unify the criteria and to standardize the dissemination of knowledge about post-harvest technologies.