Contaminants were examined for trends over time, spatial variation based on disparate breeding areas, and relationships with measures of productivity. Most organochlorines and metals declined over time. Mercury was the only contaminant with possibly increasing concentrations in eggs. Egg and feather samples collected in 2000 will provide more information on mercury trends and effects. This study embodies 20 years of data on environmental contaminants in peregrine falcons nesting in Alaska.