Technical Abstract: In 1991-93, ergot was detected in 36, 44, and 62%, respectively, of fields of Kentucky bluegrass grown for seed in central Oregon. Relatively few fields (2-13%) had a high level of ergot. Ergot severity (percent sclerotia by weight) in 1991-1993 was estimated at 0.85, 0.07, and 0.34%, respectively. Recleaning of seed to reduce ergot contamination and meet purity standards resulted in a 7.8% reduction in marketable seed weight. Weed grasses supporting ergot at the time of harvest of Kentucky bluegrass were species of Bromus, Secale, Festuca, and Poa. However, very few weed grasses were infected and they appeared to contribute little to ergot development in Kentucky bluegrass in central Oregon. Most infested fields (with more than one sclerotium/gm seed) or weed grass sites were located in the southern range of the production area.