A study of cancer mortality among laundering and dry cleaning workers was conducted. The records of the National Occupational Mortality Surveillance (NOMS) system, a NIOSH database of occupational data taken from death certificates in 28 states, were searched to identify all deaths that occurred in laundering and dry cleaning workers between 1979 and 1990. Proportionate mortality ratios (PMRs) were computed for the workers using mortality rates for mortality for decedents in all occupations as the reference. Proportionate cancer mortality ratios (PCMRs) were similarly computed. A total of 8,163 cancer deaths occurred among laundering and dry cleaning employees during the study period. Of these, 2,157 occurred in subjects 15 to 64 years (yr), 307 occurred to black males, 582 to white males, 659 to white females, and 609 to black females. The remaining 6,006 deaths occurred in persons 65yr or older, 358 among black males, 1,293 to white males, 3,074 to white females, and 1,281 to black females. Among decedents aged 15 to 64yr, significant excesses of mortality from all cancers and esophageal cancer were seen in black males, PMRs 130 and 215, respectively, and from laryngeal cancer in white males PMR 318 and PCMR 315. Mortality from cancer of the esophagus was nonsignificantly increased in black and white females, PMRs 184 and 188 and PCMRs 164 and 205, respectively. Mortality from respiratory system cancer was nonsignificantly increased in black and white males and black and white females, PMRs varying from 106 to 132 and PCMRs from 102 to 126, respectively. Cancer of the penis and other male genital organs was significantly increased in white males, PMR and PCMR 1,490 and 1,493, but this finding was based on only two deaths. Among decedents 65yr or older, mortality from breast cancer was significantly increased in white males, PMR and PCMR 1,275 and 1,277, respectively, but this was based on only four cases. Mortality from respiratory system cancer was nonsignificantly increased in black females, PMR 128. The authors conclude that these results add to the evidence that laundry and dry cleaning workers may be at excess risk for some specific cancers. The results also emphasize the need to implement effective measures to control exposures to tetrachloroethylene (127184) and other chlorinated hydrocarbon solvents used in the dry cleaning industry.