Breast cancer patients have voiced dissatisfaction regarding their education on breast cancer-related lymphedema risk and risk reduction strategies from their clinicians. Informing patients about lymphedema can contribute to decrease their risk of developing the condition, or among those already affected, prevent it from progressing further. In this cross-sectional study, a lymphedema awareness score was calculated based on responses to a brief telephone interview conducted among 389 women diagnosed with invasive breast cancer at Kaiser Permanente Northern California from 2000 to 2008 and had a previous record of a lymphedema-related diagnosis or procedure in their electronic medical record. During the telephone interview, women self-reported a lymphedema clinical diagnosis, lymphedema symptoms but no lymphedema diagnosis, or neither a diagnosis nor symptoms, and responded to questions on lymphedema education and support services as well as health knowledge. Multivariable logistic regression [odds ratio (OR) and 95 % confidence interval (CI)] was used to determine the associations of selected sociodemographic and clinical factors with the odds of having lymphedema awareness (adequate vs. inadequate). The median (range) of the lymphedema awareness score was 4 (0-7). Compared with patients <50 years of age, patients 70+ years of age at breast cancer diagnosis had lower odds of adequate lymphedema awareness (OR 0.25; 95 % CI 0.07, 0.89), while patients 50-59 and 60-69 years had greater odds of adequate awareness although not statistically significant (OR 2.05; 95 % CI 0.88, 4.78 and OR 1.55; 95 % CI 0.60, 4.02, respectively; p for trend = 0.09). Higher educational level and greater health literacy were suggestive of adequate awareness yet were not significant. These results can help inform educational interventions to strengthen patient knowledge of lymphedema risk and risk reduction practices, particularly in an integrated health care delivery setting. With the growing population of breast cancer survivors, increasing patient awareness and education about lymphedema risk reduction and care after cancer diagnosis is warranted.