The recent decrease in breast cancer mortality has been linked in part to increased breast cancer screening. Although the percentage of women screened once is rising, rate of continued adherence is poor. The purpose of this article is to assess the effects of tailored mammography interventions implemented prospectively in a factorial design contrasting groups receiving either (a) usual care (no intervention), (b) tailored telephone counseling for mammography, (c) tailored mailed materials promoting mammography, or (d) a combination of tailored mail and telephone counseling. This prospective, randomized study with a 2 x 2 factorial design included women 51 years and older (N = 1,367) who were not adherent with mammography at baseline. The intervention is based on integration of the Transtheoretical and Health Belief Models. Participants were enrolled in one of two health maintenance organizations or seen in a university-related primary care clinic. Baseline data were collected on mammography history and beliefs and knowledge related to mammography. Data were collected via telephone interviews using previously developed scales. The follow-up interviewers were conducted with 976 women. The sample was 41% White, 56% African American, and 3% other. Mean age at baseline was 66.5. Logistic regression indicates that postintervention mammography status in all three intervention groups was significantly better than usual care, with odds ratios ranging from 1.66 (telephone only) to 2.16 (telephone plus mail).