Background: It is unclear whether there are racial/ethnic disparities in lung cancer incidence and mortality among women. Therefore, we examined lung cancer incidence and mortality in the Women’s Health Initiative (WHI), a prospective cohort of post-menopausal women. Methods: Lung cancer diagnoses were centrally adjudicated by pathology review. Logistic regression models estimated odds of incidence and mortality by race/ethnicity adjusted for age, education, calcium/vitamin D, BMI, smoking (status, age at start, duration and pack-years), alcohol, family history, oral contraceptive, hormones, physical activity, and diet. Results: The analytic cohort included 129,951 women -108,487 (83%) white (47.5% current/ past smoker); 10,892 (8%) Black (47.7% current/ past smoker); 4,882 (4%) Hispanic (33.7% current/past smoker); 3,696 (3%) Asian/Pacific Islander (A/PI) (26.2 % current/past smoker); 534 American Indian/Alaskan Native (48.3% current/past smoker) and 1994 (1.4%) other (41.6% current/past smoker). In unadjusted models Hispanics had 66% lower odds of lung cancer compared with whites (OR 0.34 95% CI (0.2-0.5)), followed by A/PI (OR 0.45 95% CI (0.27-0.75)) and blacks (OR 0.75 95% CI (0.59-0.95). In fully adjusted multivariable models, decreased risk of lung cancer for blacks, Hispanics, and A/PI compared to whites was no longer statistically significant. In unadjusted models Hispanics and A/PI had decreased risk of death from compared to whites (OR 0.3 95% CI (0.15-0.62), OR (0.3 95% (0.16-0.75)), respectively); however, no significant racial/ethnic differences were found in risk of death from lung cancer in fully adjusted models. Conclusions: We found no racial/ethnic disparities in lung cancer incidence or mortality in a population of post-menopausal women after adjusting for socio-demographic, clinical, and behavioral factors. Clinical trial information: 1757.