The role of seed and pollen in the spread of pathogens is discussed. With the exception of mycoplasmas all other groups of pathogens can be seed transmitted. It is important to understand where and how the pathogen is located in the seed and examples are given of how various pathogens are transmitted. Storage of seed may reduce but not eliminate inoculum of important pathogens. Pollen provides a valuable tool for crop improvement but exchange of pollen risks introducing plant pathogens into new areas. A number of viruses, as well as a few bacteria and fungi, are pollen transmitted. Seed inspection and health tests are important for the detection of seed-borne pathogens. Some of the tests used are described.