This report documents the impacts of international maize breeding research in eastern and southern Africa. It draws on information from a comprehensive 1998/99 survey of public and private maize breeding and seed production organizations active in the region. In many countries of eastern and southern Africa, policy reforms introduced in the 1980s and 1990s encouraged private sector participation in the maize seed industry. The private sector now supplies most of the maize seed in the region, spends more on research, and generates a larger number of maize releases than the public sector. Hybrids dominate varietal releases and seed sales, a trend that may negatively affect subsistence-oriented farmers who lack resources to buy fresh seed every season. Although farmers' adoption of improved maize varies throughout the region, it has increased steadily. Survey data show that CIMMYT's maize breeding program has had significant impacts in eastern and southern Africa, especially in recent years. Of the maize varieties released in the region since 1990, 31% (55% if South Africa is excluded) were developed using CIMMYT breeding materials. In 1996, more than 1.6 million hectares in eastern and southern Africa were planted to varieties developed using CIMMYT germplasm. The varietal release data and adoption data indicate growing demand for CIMMYT breeding materials from both public and private breeding programs, as well as growing acceptance by farmers of varieties developed using those materials.