Interactions between public and private sector organizations in the world maize seed industry are analyzed, with emphasis on the developing world. Information is presented on the share of total maize seed sales in 1992 by different kinds of seed enterprise and by different types of seed (hybrids, open pollinated varieties) and its origin (public or private sector breeding programs). In most developing countries, private organizations remain the major producers and distributors of maize seed; maize seed production and distribution by the public sector has tended to diminish. Public breeding systems, however, are still important in maize seed industries; more than half of the seed sold in developing countries in 1992 was of public origin. Although schemes for direct production and distribution of maize seed by the public sector are largely a thing of the past, public breeding systems will remain important for fostering the development of domestic private seed enterprises and small-scale seed producers, and conducting research directed at small-scale farmers.