For several years, the Asian countries have had the highest rate of increase (3.6%) in maize production in the world. This has been due to the increasing demand of the grain for food, feed, and industrial purposes. Undoubtably, the largest volume has been directed to be used as animal feed. One of the basic CIMMYT philosophies is to assist national programs in increasing their maize productivity. We believe that this broad objective can be achieved through the availability of improved maize germplasm, training of scientists, and technical consu1tancies. As part of the technical upgrading of scientists in the region, we believe that one important way to assist researchers in keeping pace with new scientific developments in our area of research, is through scientific meetings where we all can learn about the activities and experiences of colleagues in other programs. On this occasion, the CIMMYT Asian Regional Maize Program (ARMP) and the National Maize Program of the Soc. Rep. of Vietnam co-sponsored this 5th Asian Regional Maize Workshop, held in Vietnam November 15-20, 1993. Being aware of the several success stories cited on hybrid maize in several countries, both in the developed and developing world, it was suggested that the theme of this 5th WOrkshop be on Hybrid Maize in Asian Countries. It will be through learning of the experiences of other countries in the region already involved in hybrid development that we can benefit from their positive experiences and avoid repeating those that represented setbacks in the adaptation of hybrid technology. Technical sessions were held in both Hanoi and Ho Chi Minh City. There were presentations by representatives from various national maize programs from countries in the Asian region. We also had the participation of the FAD/RAPA Regional Plant Production and Protection Officer Representative who described the regional activities of that organization. Colleagues from private seed companies operating in the region also presented their activities on research and development of new germplasm. It is through this open relationship that we can all benefit from each other by increasing knowledge and experiences, improving our research which in turn will benefit the farmers in the region. As in previous Asian Regional Maize Workshops, two Demonstration Nurseries were planted at two different environments, one at the Maize Res. Institute, Don Phuong in the North and the other one at the Hung Loc Expt. Stat. of the Inst. of Agric. Sci. in the South of Vietnam. These nurseries were planted to give an opportunity to participating scientists from various government and private sectors to submit and observe the varieties they have developed in their programs and the varieties developed by other programs in the region. A total of 241 entries were included in these Demonstration Nurseries. We have routinely encouraged the participants to request to the respective programs any entry that might be useful in their own programs. CIMMYT also included some of its high yielding, agronomically desirable experimental varieties with wide adaptation across locations in Asian countries. Special entries in the nurseries included those selected for tolerance/resistance to drought, acid soils, low nutrients, insects, and diseases. We would like to acknowledge the very positive response of Cargill Seeds Co., Ciba Geigy (Thailand) Ltd., Charoen Seeds Co., ICI-Pacific Seeds Co., and Pioneer Overseas Corp., in financially supporting the trip of Dr. Arnel R. Hallauer, Prof. of Plant Breeding and Genetics, Iowa State Univ., to participate in this Workshop. Our appreciation goes also to Bioseed Genetics (Vietnam) and Maharashtra Hybrid Co. (MAHYCO) from India for sponsoring one banquet each the days of opening (Hanoi) and closing (Ho Chi Minh City) of the Workshop. CIMMYT thanks you all for your interest and invaluable partnership in our activities. To close this Foreword, our appreciation for Mrs. Chiraporn for spending so many extra hours typing these Proceedings.