The major factors limiting duck nesting and production on intensively farmed areas in eastern North Dakota [USA] were studied from 1969-1974. A total of 186 duck nests was found during searches on 6018 ha of upland. Nest density per km2 for 5 major habitat types was 20.2 in untilled upland, 3.7 in standing grain stubble, 1.6 in mulched grain stubble, 1.2 in summer fallow, and 1.1 in growing grain. Pintails (Anas acuta) nested in cultivated cropland types in greater prevalence than other duck species. Nest densities were 12 times greater on untilled upland (20.2/km2) than on annually tilled cropland (1.7/km2), and hatched-clutch densities were 16 times greater on untilled upland (4.8/km2) than on annually tilled cropland (0.3/km2). Hatching success was greater on untilled upland (25%) than on tilled cropland (17%). Of 186 nests found, 77% did not hatch; 76% of the failures were attributed to predators and 19% to farming operations. Poor quality nesting cover, the result of intensive land use practices, and nesting failures caused by machinery and predators, mainly mammals, were the principal factors limiting duck nesting and production on intensively farmed areas.