This working guide outlines the structure and content of training for the primary health worker (PHW) on the basis of the most common health problems of communities in developing countries. Part 1 is intended for use by the PHW as a learning text and reference in his work. It covers thirty-four problems considered to be most common which are grouped under seven main headings: communicable diseases, maternal care, child health and nutrition, accidents, village and home sanitation, other common problems, and community development. A brief explanation, learning objectives, and suggested preventive measures or referral are presented for each problem. Appendixes provide a list of medicines used in this guide (administration and dosage), a few (medical) techniques, anatomical diagrams, and an index/glossary. Part 2 presents principles and methods to help instructors, supervisors, and PHWs use and teach the content of part 1. Four chapters discuss the knowledge and information basic to any training program, describe methods and techniques for making learning/teaching more effective, discuss assessment of the training, and give examples of how to organize learning modules. Part 3 discusses adaptation of the book for use in a particular country in accordance with its needs, structures, and potentialities. (YLB)