The National Occupational Mortality Surveillance System (NOMS) as a research tool for investigating work related diseases in female workers was discussed. NOMS was a death certificate based surveillance system involving the participation of 28 states managed by NIOSH. Information on the usual occupation and industry of each decedent coded according to the 1980 Bureau of the Census Classification System was included on the death certificate. NOMS could be used to obtain occupational mortality for a broad geographical area which covers a wide range of industries and occupations. It could also be used to identify previously unrecognized work related diseases and to target consultative or health promotion programs in appropriate occupations. NOMS has been used to study mortality of all working women 20 years or older from 1985 through 1990. Death certificate data for 369,739 white females and 40,080 black females were analyzed, from which proportional cancer mortality ratios (PCMRs) were computed. Selected results from this study were presented. An analysis of leukemia mortality found significant excesses among white women employed as pharmacists, teachers, librarians, archivists, and curators, clinical laboratory technicians, production supervisors, and production testers, PCMRs 209, 113, 141, 162, 148, and 409, respectively. Leukemia mortality was significantly elevated in black females employed as private household cooks, PCMR 234. Leukemia mortality was nonsignificantly increased in black females employed as clinical laboratory technicians. It was noted that while some associations may be due to chance, others such as clinical laboratory technicians may represent biologically plausible associations since these may involve exposure to known leukemogens such as benzene (71432), ionizing radiation, or viruses. The authors conclude that the NOMS system is a valuable addition to the data sources available for surveillance of occupational health outcomes among working females. The system does have limitations in that death certificate information regarding occupation and cause of death may not be accurate and the fact that death certificates provide little information on smoking or other confounding factors.