Greater Prairie-Chicken populations have declined, primarily from loss of their prairie habitat to agriculture and other human development. As wind energy projects are proposed in Kansas and other states where Greater Prairie-Chickens and other grassland birds are now of conservation concern, conservationists, wildlife agencies, and wind energy companies are collaborating to study possible impacts from such development. Results from a comprehensive seven-year research project in Kansas suggest that wind power does not strongly affect Greater Prairie-Chickens. While weak negative effects were observed in male attendance of leks (communal display sites), female survival showed a positive trend. Little to no impacts were observed on most of the demographic parameters studied. The strongest correlates of population performance were the availability of native prairie and vegetative cover at the nest site. Efforts to improve rangeland management and to reduce predation would aid in the recovery of Greater Prairie-Chicken populations.