Objectives We investigated factors associated with primary and secondary breast and cervical cancer screening among American Indian (AI) women receiving care from the Indian Health Service (IHS) in Montana and Wyoming. Methods. Rates of primary screening (i.e., screening without evidence of a prior abnormal) and secondary screening during a three-year period (2004-2006) were determined in an age-and clinic-stratified random sample of 1,094 women at six IHS units through medical record review. Results. Three-year mammography prevalence rates among AI women aged ≥45 years were 37.7% (95% confidence interval [CI] 34.1, 41.3) for primary and 58.7% (95% CI 43.9, 73.5) for secondary screening. Among women aged ≥18 years, three-year Pap test prevalence rates were 37.8% (95% CI 34.9, 40.6) for primary and 53.2% (95% CI 46.0, 60.4) for secondary screening. Primary mammography screening was positively associated with number of visits and receiving care at an IHS hospital (both p<0.001). Primary Pap test screening was inversely associated with age and positively associated with the number of patient visits (both p<0.001). Secondary mammography screening was inversely associated with driving distance to an IHS facility (p50.035). Conclusion. Our results are consistent with other surveys among AI women, which report that Healthy People 2010 goals for breast (90%) and cervical (70%) cancer screening have not been met. Improvements in breast and cervi cal cancer screening among AI women attending IHS facilities are needed.