Women with developmental disabilities are significantly less likely than women without disabilities to receive cervical and breast cancer screening according to clinical guidelines. The reasons for this gap are not understood. The present study examined the extent of women's knowledge about cervical and breast cancer screening, with the intention of informing the development and testing of interventions to increase cervical and breast cancer screening rates for these women. In a sample of 202 community-dwelling women with developmental disabilities, most women had little knowledge of cervical and breast cancer screening. Women who were living at home with family caregivers had the most limited understanding of cervical and breast cancer screening. Policy and practice implications are discussed.