Good quality seed is thought of in terms of high analytical purity, high germination percentage, and freedom from seed-borne diseases. The obligation of administrators and leaders at all levels of a seed program to assure farmers of good seed quality of improved varieties is complicated by the inability of any one person or organization to control the quality of all seed used. A seed certification program is one tool for producing genetically pure, good quality seed of improved varieties. Seed certification is a system that incorporates certain basic steps: determining the eligibility of varieties, verification of seed source, field inspection, sampling, seed testing against quality standards, labeling, conducting variety control plots, and education and information. Seed certification, enforcement of seed marketing laws, and seed testing are organized in various ways around the world. A national seed board should be responsible for the total seed program including the national seed center.