ICRAF has undertaken to develop an interdisciplinary Diagnostic and Design methodology for agroforestry, to assist agroforestry workers in identifying priorities for technology-generating research, based on designs for appropriate agroforestry technologies derived from a diagnosis of the needs and potentials of land use systems. After initial development and testing of the D&D methodology in more than twenty sites around the world over the past two years, ICRAF has produced these draft Guidetines for AgrofoPe8t~ Diagnosis and Design and a companion volume entitled Resouraes for Agroforest~ Diagnosis and Design. They are being published in working paper form in order to facilitate early dissemination and wider field testing of the evolving methodology and to elicit comments and suggescions for improvements to be incorporated into subsequent editions. The present document provides an introduction to the Diagnostic and Design methodology, covering the logical framework of the methodology, an outline and description of the step-by-step procedures, a discussion of manpower requirements, the scale and timing of D&D activities, institutional considerations, etc. Although the emphasis is on the use of the D&D methodology at the formulation stage of agroforestry projects, the role of the continuing diagnosiS and design process as part of the project's 'internal guidance system' is also discussed. For more detailed procedural guidelines and a variety of useful tools and materials, the reader is referred to the companion document