Published by the American Geophysical Union as part of the Short Courses in Geology Series, Volume 1. The catastrophic eruption of Mount St. Helens on May 18, 1980, inaugurated the worst decade of volcanic disasters and crises since 1902, the year when three eruptions in a 6-month period (Mont Pelée, Martinique; Soufrière, St. Vincent; and Santa Maria, Guatemala) claimed more then 36,000 human lives (Tilling, 1989, in press). The volcanic disasters and crises in the 1980's greatly enhanced scientific and public awareness of volcanic eruptions and associated hazards, spurred advances in volcanology and the establishment of new volcano observatories, and launched numerous international conferences, symposia, and workshops on volcanic-hazards topics. Thus, it was fitting that the organizers of the 28th International Geological Congress [IGC] (Washington, D.C., July 9-19, 1989) and the General Assembly on Continental Magmatism of the International Association of Volcanology and Chemistry of the Earth's Interior [IAVCEI] (Santa Fe, New Mexico, June 25-July 1, 1989) decided to offer a jointly sponsored "Short Course on Volcanic Hazards." The chapters herein provide the framework for the two-day short course, to be convened July 2-3, 1989, at the College of Santa Fe, New Mexico. This short course, also co?]sponsored by the Division of Earth Sciences of the United Nations Educational, Scientific and Cultural Organization [UNESCO] (Paris), will be open to registrants of either the IGC or the IAVCEI meeting. Obviously, the vast topic of volcanic hazards cannot be treated comprehensively in only two days. The primary aim of the short course is to review some basic principles and methods of the mitigation of volcanic hazards, with special focus on the developing countries, which contain most of the world's dangerous volcanoes. In addition to lectures and classroom discussion, the short course also includes a half-day field excursion to examine volcanic deposits and features and to demonstrate some volcano-monitoring measurements.