The study was undertaken to determine the fate of endrin in a food chain situation involving the soybean plant, Glycine, Max L. (Leguminosae), the Mexican bean beetle, Epilachna varivestis Muls. (Coccinellidae), and the eastern bobwhite quail, Colinus virginianus virginianus L. (Perdicidae). Beetles contaminated withendrin were force-fed to birds at 1 mg/kg/bird, in both acute (4 hr) and chronic (5 day) exposures. Contaminated beans were force-fed to birds at 0.015 mg/kg/ bird, in similar acute and chronic rates. Endrin concentrated primarily in the fat, liver, and gonadal tissues of the birds. Analyses of whole birds revealed retention of approximately 16% of the total acute dose administered, and 21% retention of the total chronic dose. At sensitivities used for analyses, no metabolites were detected in any component of the food chain. The eastern bobwhite quail, Colinus virginianus virginianus L., long has been recognized as the most important game bird in South Carolina. During recent years concern has developed among conservationists regarding exposure of this and other birds to pesticide residues in the environment. This concern has been shared by many scientists (Bernard, 1963; DeWitt, 1956; DeWitt, Stickel and Springer, 1963; Eden, 1951; George, 1963 ; James and Davis, 1965; Moore, 1964; Rudd and Genelly, 1956; Rudd, 1964; Sherman and Rosenberg, 1954; and Stickel and Stickel, 1964). Although endrin usage on soybeans, Glycine Max L., has never been recommended in South Carolina, it has been used for pest management in the past. Recently, insecticides of the chlorinated hydrocarbon type have been shown to be absorbed from soils into various plants (Marth, 1965). This is noteworthy since endrin has been used on cotton in South Carolina and could enter the soybean plant via soil accumulations. During the last decade much data has been accumulated, with the aid of refinements in analytical techniques, to show that most chlorinated hydrocarbon insecticides pentrate plant tissues and are translocated at least to a limited extent (Beck et al., 1962; Bruce, Lind and Decker, 1965; Lichtenstein and Schulz, 1960; Maier-Bode, 1965; and Popham and Hale, 1958). Endrin residues were found in about three fourths of the soybean samples from Arkansas and Mississippi (Pesticides Monitoring Journal, 1968). Mexican bean beetles, Epilachna varivestis Muls., both in the larval and adult stages, feed readily on most varieties of the soybean plant (Pallister, 1949). Davison (1958) reported that plants supplied about 85% of the bobwhite's food, the other 15% being animal foods. Martin (1935) found that soybeans ranked ninth out of 46 food items in preference by bobwhite quail.