Technical Abstract: Endophytic fungal infections in grasses can have a beneficial and/or detrimental effect on plant stress and development. The presence of Neotyphodium spp. fungal endophytes in grasses impart biotic and abiotic stress tolerance, however, they also can severely impact forage quality due to production of toxic alkaloids. While the endophytic fungus Epichloe typhina is the causal agent of choke in grasses, disrupting seed head formation and development. A reliable, flexible and rapid method to detect fungal endophytes in various plant tissues and seeds is need. Polymerase chain reaction (PCR) methods for detection of Epichloe typhina in orchardgrass plants (Dactylis glomerata L. ) and Neotyphodium endophytes in seed and plant tissue from tall fescue and ryegrass were developed. PCR primers based on an intron in the actin 1 gene amplify a 481 base pair diagnostic product corresponded to presence of E. typhina. While in tall fescue and ryegrass, Neotyphodium spp. was detected using primers designed to amplify products from a region of the tubulin 2 gene. These PCR methods provide an accurate and sensitive approach for detecting the presence of these endophytes in different grass species, while maintaining enough specificity to readily discriminate against related fungal contaminants such as ergot.