There is legitimate concern about whether cancer screening programs and other types of prevention and early detection programs are designed to reach those most in need of services. Previous research on barriers to screening has generally addressed screening for specific cancers. The purpose of this study was to evaluate and compare the types and strengths of barriers to both mammography and Pap smear screening experienced by three groups of women. Five hundred and twenty-two women, aged 52-69, who were members of a large health maintenance organization (HMO), completed a survey about cancer screening and associated barriers. Women with no mammogram in the preceding 2 years and with no Pap smear in 3 years were classified into a "safety net" program. We classified women as falling into both (Pap smear and mammography), one (Pap smear or mammography), or neither safety nets. Results consistently revealed that women needing both tests had more numerous and more intense barriers than other women to both types of screening. Factor analyses and descriptive analyses both showed that the types of barriers experienced were very similar for mammography and Pap smear screening. The discussion addresses intervention implications and the additional research needed on women who need both mammogram and Pap smear screening and who have much higher cancer risk than other women.