Grasslands are among the most threatened habitats in North America and populations of many grassland birds, including Northern Harriers (Circus cyaneus), are declining. While native grasslands are disappearing, current procedures for reclaiming surface mines have produced large areas of grasslands in the eastern United States. Currently, little is known about the use of such grasslands by raptors. The objective of this study was to examine the nesting behavior of Northern Harriers on a reclaimed surface mine grassland in Kentucky. Over two breeding seasons (April–July 2002–03), 46 harrier nests were located, and young fledged from 10 (21.7%) of these nests. All but one nest were located in dry, upland areas, and the increased vulnerability of nests in such sites to predation may have contributed to this relatively low nesting success. Successful nests were located in denser vegetation than unsuccessful nests, suggesting that greater concealment may reduce predation risk. The percentage of breeding females that were subadults (44.4%) was higher in this Kentucky population than reported elsewhere, although nest success did not differ with female age. Most prey items delivered to nestlings were small mammals (134 of 139; 96.4%), with male harriers capturing most prey and, in aerial exchanges, transferring those prey to females for delivery to the nest. These results suggest that Northern Harriers can breed successfully on reclaimed surface mine grasslands.