A study of cancer mortality in garment workers exposed to formaldehyde (50000) was conducted. The cohort consisted of 11,030 workers employed at three factories where shirts were manufactured from formaldehyde treated fabrics between 1955 and December 31, 1977. Vital status of the cohort as of December 31, 1982 was determined. Death certificates were examined. Standardized mortality rates (SMRs) were computed using expected death rates of the United States population as the reference population. Industrial hygiene sampling for formaldehyde, phenol (108952), organic vapors, and nuisance dust was done at the facilities. A total of 609 deaths occurred, for which 587 death certificates were obtained. Geometric mean formaldehyde exposures were 0.14 to 0.17 parts per million (ppm). No phenol was detected. Organic vapor exposures ranged from nondetectable to 5.0ppm for methylchloroform (71556) and up to 1.0ppm for 1,1,2-trichloroethane (79005). Nuisance dust concentrations ranged up to 1.5mg/m3. Mortality from cancer of the buccal cavity and connective tissue was significantly elevated, having SMRs of 343 and 364, respectively. Nonsignificant excesses of mortality from cancer of the trachea, bronchus, and lung, pharynx, bladder, leukemia and aleukemia, and other lymphopoietic neoplasms were observed. With the exception of cancer of the trachea, bronchus, and lung, cancer mortality increased with increasing duration of exposure or latency. Mortality from cancer of the trachea, bronchus, and lung appeared to be inversely related to duration of exposure or latency. The authors conclude that the results, although not conclusive, suggest a possible relationship between formaldehyde exposure and upper respiratory cancers, leukemias, and lymphopoietic neoplasms.