This paper examines adherence to a referral for a screening mammogram among an ethnically diverse sample of 576 female county health department patients age 50 and over. Data were obtained by interview approximately one year after the referral for a screening mammogram. Overall, approximately 80% of the sample were adherent to the referral. Medical record validation of self-reports of mammography receipt verified receipt of a mammogram for 82% of those reporting one. In logistic regression analysis, determinants of adherence included: transportation barriers, fear of immigration authorities, perceived control over getting breast cancer, self-rated health status, age, and perceived quality of provider-patient communication. The most prevalent concerns about mammography were concern over finding cancer, treatment for breast cancer, and removal of a breast. Reporting of these concerns was not significantly related to adherence. Also reported are barriers to health care experienced by this population over the past 12 months. The high adherence rate found in this study emphasizes the importance of provider referral in the delivery of screening mammography, and invalidates assumptions that women of lower education and lower income are less likely to adhere to provider recommendations.