Background: Following reforms to our city's Safety-Net (SN) breast cancer referral process, we investigated whether factors often associated with late-stage diagnosis would differ by referral source-SN versus non-Safety-Net (NSN)-or, among SN patients, by stage at diagnosis. Methods: From September 2008 to June 2010, SN patients with any-stage (0-IV) and NSN patients with late-stage (IIB-IV) breast cancer were identified prospectively during initial cancer-center consultations. Data were analyzed using logistic regression, chi-square, and t tests; two-tailed P < 0.05 was considered significant. Results: Fifty-seven women completed interviews (33 SN, 24 NSN); 52 % of SN-referred patients were diagnosed with late-stage disease. Compared with NSN late-stage patients, SN late-stage patients were more likely to be African-American (83 % vs. 21 %, P < 0.001), to have an annual household income <$25,000 (89 % vs. 38 %, P < 0.001), and to report having a health problem in the preceding year but not being able to see a doctor because of cost (67 % vs. 25 %, P = 0.012); they were less likely to be married/partnered (22 % vs. 79 %, P < 0.001) and to have post-college education (0 % vs. 25 %, P < 0.03), any insurance (61 % vs. 96 %, P < 0.005), and to have sought medical attention within 1 week of realizing they had concerning breast findings (50 % vs. 79 %, P = 0.047). Married/partnered patients were more likely to delay medical care by >1 week (odds ratio = 9.9, P = 0.038). Conclusions: SN patients presented with higher-than-expected rates of late-stage disease despite improvements in mammography rates and the referral process. Efforts to further facilitate access to care for this vulnerable SN patient population are needed.