This publication presents the proceedings of the Science Writers Workshop, sponsored by the Department of Energy (DOE) as part of the Human Genome Initiative. The participants included scientists from industry, academia, and several national research laboratories in the United States as well as scientists from around the world. It consists of short individual papers summarizing a particular topic. These papers are all written for the scientifically literate person, not for the expert in molecular genetics. The organization proceeds from historical overview to specific papers summarizing the progress in mapping and sequencing the human genome. Both scientific and social issues are addressed. The paper by Wada, from Tokyo, reviews the efforts at largescale technology which must be developed if the Human Genome Project is to be successful. Of particular interest to the general reader is the roundtable discussion, which included representation from the DOE, academic science, clinical medicine, and biomedical ethics. It addresses the broad scientific, social, and medical issues surrounding the Human Genome Project, ranging from improved understanding of evolution to implications of genetic screening in the workplace. The book is highly readable. How could a symposium for science writers be less? The illustrations are clear, and the examples make some complex material readily understandable. In less than 200 pages, the reader can gain a very complete overview of the Human Genome Project as it was regarded up to 1987. Therein lies the only major disadvantage to the book. Three years is a long time in molecular genetics. Many advances have been made since then. This volume could, however, provide the needed background to introduce those who have not been in the genetics arena to the excitement and advantages as well as the pitfalls of the Human Genome Project. The tools of modern molecular genetics will be very powerful; this book will help the non-geneticist to gain an understanding of them.