The success of the genetic modification of plant species for insect and virus resistance and herbicide tolerance has led to the rapid development of improved commercial varieties for many crops. There are over 40 different genetically modified plant products that have been approved in at least one country, and about 30 million acres of genetically modified plant varieties were planted in 1997 (James 1997). One of these products, the insect-protected corn event MON 810 (YieldGardTM) expresses the Bacillus thuringiensis protein Cry 1Ab. YieldGardTM corn is protected from feeding damage normally caused by the European corn borer (ECB, Ostrinia nubilulis), southwestern corn borer (SWCB, Diutrueu grundiosellu), and pink borer (Sesamiu crericu). A critical step in the commercial development of these products is gaining regulatory approvals for both production and import of the genetically modified plant products. Food, feed, and environmental approvals, and, in some countries, variety registration for new plant varieties, are necessary for genetically modified plants. This chapter is an overview of the information developed and provided to the regulatory agencies to obtain food, feed, and environmental approvals for YieldGardTM corn. Variety registration is the same for varieties developed through traditional breeding or biotechnology and therefore is not discussed in this chapter.The European corn borer (ECB, Ostriniu nubilulis) (Hubner) is an economically important pest of corn that has spread throughout the major corn-growing regions of the United States and Europe (Showers et al. 1989). Yield losses due to ECB damage are estimated to be 3 to 7% per borer per plant (Lynch 1980; Gay 1993), which causes annual losses from $37 to $172/ha of corn (Rice 1994). This insect typically has one to three generations per year. Insect damage to the plant includes leaf feeding by the first generation; stalk tunneling by the first and second generations; and leaf sheath, collar feeding, and ear damage by the second and third generations. Chemical control is ineffective once the borers have tunneled into the plant because the insect pest is then inaccessible to the chemical.