Legesse Wolde-Yohannes is an Ethiopian horticultural scientist. He cooperated with Aklilu Lemma on the discovery and research on how to use the plant endod as a means of preventing the parasitic disease bilharzia. He was awarded the Right Livelihood Award in 1989, jointly with Lemma. Bilharzia, or schistosomiasis, is a debilitating and eventually fatal illness, which afflicts more than 200 million people in 74 countries of Africa, Asia and Latin America. Present therapies for bilharzia, and molluscicides to kill the snail-carriers of the disease, are far too expensive for the communities that need them. In 1964 a young Ethiopian doctor, Aklilu Lemma, discovered that suds from the fruit of a common African plant, the endod or soapberry, which African women have used as soap for centuries, act as a potent molluscicide. To follow up this discovery, Lemma in 1966 established the Institute of Pathobiology in Addis Ababa University, and for the next 10 years he directed a team to carry out systematic research on endod. He was joined in this work in 1974 by Legesse Wolde-Yohannes. The discovery seemed to offer no less than a cheap, locally-controllable means of eradicating a disease that is the second greatest scourge in the Third World. And Lemma's early research confirmed this potential. Yet progress in making this endod product available to the people who need it has been extremely slow, for reasons that expose some of the biases and failings of the international medical community. In the last few years, however, Lemma's and Wolde-Yohannes' persistence and the support of key scientists and donors in the West has opened the door to the necessary laboratory and field trials. An endod research and application network has also been established, linking five African countries, and the plant is being grown and used for experimental control of schistosomiasis. Before his death in 1997, Lemma and colleagues established the Endod Foundation to serve as an umbrella for all endod-related work. Following collaboration with Lemma, the University of Toledo, USA, was granted a US patent on an endod-based molluscicide intended to control the zebra mussels which have recently invaded American lakes and caused extensive damage to water supplies. This has opened a major new hope for marketing and exporting endod as a cash crop. Legesse Wolde-Yohannes has a doctorate in Horticultural Science from the Technical University of Hannover, Germany. He has coordinated endod research in Addis Ababa since 1980, developing methods for its extraction and application and carrying out relevant agrobotanical studies. He is currently an Associate Professor of Biology at Addis Ababa University and also serves as Director of the National Endod Foundation. Dr. Legesse Wolde-Yohannes has published several articles on endod cultivation and extraction, soil science plant nutrition and is co-author of a handbook on endod utilisation. He has organised national and international seminars and workshops on endod/bilharzia and carried out several WHO consultancy missions to Africa, USA, Canada and Europe in relation to the use of endod for schistosomiasis and zebra mussels control programmes. For his scientific achievement, Dr. Legesse Wolde-Yohannes received the Golden Medal from the University of Oslo, Norway in 1989 and the Golden Medal and Certificate of Merit from Addis Ababa University in 2000. Since 1999 Dr. Legesse Wolde-Yohannes is senior advisor on endod and medicinal plants to the Ethio Agri-CEFT Private Limited Company. He is involved in promoting agrobotanical studies on endod and other medicinal plants towards large-scale production and processing for local and international marketing.