Background: Chemotherapy with both anthracyclines and taxanes sequentially or concurrently (ACT) has improved survival in breast cancer. A regimen containing docetaxel and cyclophosphamide (TC) was developed to avoid cardiac side effects, which are of particular concern in older women. The efficacy of ACT vs. TC is under investigation in NSABP B-49, but results are not yet available. We examined temporal trends and clinical associations with ACT vs. TC use in clinical practice in older women and compared the overall survival of patients receiving adjuvant ACT vs. TC. Methods: We used the SEER-Medicare database for women over 65 diagnosed 2004-2009. Women were classified by regimen received: ACT, TC, and other (including anthracycline without taxane and cyclophosphamide, methotrexate, and 5-fluorouracil). We excluded women who received trastuzumab. We used chi-square and logistic regression to identify factors associated with ACT vs. TC receipt and Cox proportional hazards models to assess survival differences by treatment. Results: We identified a total of 4391 patients: 1577 (36%) received ACT, 1174 (22%) received TC, and 1640 received other regimens. Use of ACT decreased from 26% in 2004 to 21% in 2009, whereas use of TC increased from 1% to 43% in the same period. Receipt of ACT vs. TC was associated with younger age; fewer comorbidities; lack of history of coronary artery disease, diabetes, or atrial fibrillation; higher stage and lymph node involvement; and living in the Northeast United States (as compared to the West or South). Five-year overall survival (OS) estimates were 81% for patients receiving ACT and 86% for patients receiving TC (p = .21); 3-year unadjusted survival for stage III patients was 87% for ACT and 79% for TC (0.002). The adjusted Cox proportional hazard ratio for all patients, adjusted for stage, comorbidities, and other significant associations, was 1.10 (95% CI 0.64-1.91). The hazard ratio for ACT vs. TC was not significant for stage I/II patients, but for stage III patients was 0.59 (95% CI 0.40-0.89). Conclusions: TC has become a common choice for adjuvant chemotherapy among older patients. In all patients, 5-year OS was similar between groups, but OS may be higher for patients with stage III disease receiving ACT.