BACKGROUND: Controversy exists regarding the role of exercise in cancer patients with or at risk for lymphedema, particularly breast. We conducted a systematic review of the contemporary literature to distill the weight of the evidence and provide recommendations for exercise and lymphedema care in breast cancer survivors. METHODS: Publications were retrieved from 11 major medical indices for articles published from 2004 to 2010 using search terms for exercise and lymphedema; 1,303 potential articles were selected, of which 659 articles were reviewed by clinical lymphedema experts for inclusion, yielding 35 articles. After applying exclusion criteria, 19 articles were selected for final review. Information on study design/objectives, participants, outcomes, intervention, results, and study strengths and weaknesses was extracted. Study evidence was also rated according to the Oncology Nursing Society Putting Evidence Into Practice(R) Weight-of-Evidence Classification. RESULTS: Seven studies were identified addressing resistance exercise, seven studies on aerobic and resistance exercise, and five studies on other exercise modalities. Studies concluded that slowly progressive exercise of varying modalities is not associated with the development or exacerbation of breast cancer-related lymphedema and can be safely pursued with proper supervision. Combined aerobic and resistance exercise appear safe, but confirmation requires larger and more rigorous studies. CONCLUSIONS: Strong evidence is now available on the safety of resistance exercise without an increase in risk of lymphedema for breast cancer patients. Comparable studies are needed for other cancer patients at risk for lymphedema. IMPLICATIONS FOR CANCER SURVIVORS: With reasonable precautions, it is safe for breast cancer survivors to exercise throughout the trajectory of their cancer experience, including during treatment.