OBJECTIVES: The objective of this study is to determine the association between timeliness of breast cancer (BC) care based on the published recommendations and select factors in elderly women with BC.  METHODS: A retrospective observational cohort study was conducted utilizing Surveillance, Epidemiology and End Results (SEER)-Medicare-Area Resource File linked database.  The study cohort consisted of 66,276 elderly women age > 66 with a first primary incident BC in 2003-2009.  As per the published opinion based guidelines, two time intervals were timely diagnosis (<=35 days from the initial consultation for breast abnormality to biopsy-proven BC diagnosis) and timely treatment (<=28 days from biopsy-proven BC diagnosis to the initiation of treatment).  Logistic regressions were performed on timely diagnosis and timely treatment to determine the factors associated with timeliness of BC care in elderly women. RESULTS: As per the published opinion-based guidelines, 71% of the study cohort received timely diagnosis and 73% received timely treatment of BC.  Older age (80 and above), white race (adjusted odds ratio (AOR)=1.2, 95% confidence interval (CI)=1.1-1.3), distant BC stage, moderately (AOR=1.1, 95% CI=1.0-1.2) and poorly (AOR=1.3, 95% CI=1.2-1.4) differentiated grades of tumor, tumor size > 3 cm, no comorbidity and lower PCP visits were significantly associated with timely diagnosis of BC. However, age 66 to 74 years, white race (AOR=1.4, 95% CI=1.3-1.5), earlier stages of BC, tumor size < 3 cm, no comorbidity, higher PCP visits, and lower number of hospitals with oncology services in the area of residence were significantly associated with timely treatment of BC.  CONCLUSIONS: Approximately 30% of elderly women did not receive timely diagnosis and timely treatment of BC as per the published opinion-based guidelines.  Several patient, provider and health system factors were associated with timely BC care in elderly women.