To better understand the role of prairie landscape configuration on the population dynamics and conservation of greater prairie-chickens, we compared population trends and breeding ecology of prairie-chickens in prairie mosaic and contiguous prairie landscapes in southwestern Missouri. Over 27 yr, the contiguous prairie landscape supported a stable population, whereas the prairie-chicken population in the prairie mosaic landscape declined. In 1986 and 1987, less than one-third of greater prairie-chicken nests occurred in native prairie habitats in the prairie mosaic landscape, but 90% of nests in the contiguous prairie area were in native prairie. Greater prairie-chicken nests established in agricultural habitats had substantially lower nest success than nests in native prairie or mixed native-exotic grass pastures. Nest success was higher in the contiguous prairie landscape than in the prairie mosaic area in 1 of 2 yr. Habitat use by broods differed between the areas: in the contiguous prairie landscape we detected females with broods most often in native prairie, but brood females in the prairie mosaic were most often detected in agricultural habitats. Females with broods exhibited greater daily movement and had larger home ranges in the prairie mosaic than in the contiguous prairie landscape. In Missouri landscapes with ≤15% prairie composition, contiguous tracts of prairie, at least 65 ha, offer greater potential for greater prairie-chicken conservation, than smaller, scattered prairie tracts.