An historical cohort mortality study was undertaken at Owens Corning's continuous filament fiberglass manufacturing plant in Anderson, South Carolina. The cohort included 1074 white women, 130 black women, and 494 black men who worked for a minimum of one year from the opening of the plant in 1951 through December 31, 1991. This represents the largest single cohort of white women assembled to date in either a wool or continuous filament fiberglass manufacturing facility and represents the first study of a cohort of black men and women in the man-made vitreous fiber industry. Over 95 % of the women and minorities included in this report held production positions in the plant. There were no significant excesses or deficits in mortality by cause, including cancer causes, among white women, with the exception of motor-vehicle accidents, when compared with national mortality. Among black men, standardized mortality ratios (SMRs) for heart disease are significantly below one, and SMRs for all cancers combined are below unity on both national and local standards. Lung cancer SMRs are below unity for both white women and black men.