PURPOSE: To update the 2006 American Society of Clinical Oncology guideline on the use of hematopoietic colony-stimulating factors (CSFs). METHODS: The American Society of Clinical Oncology convened an Update Committee and conducted a systematic review of randomized clinical trials, meta-analyses, and systematic reviews from October 2005 through September 2014. Guideline recommendations were based on the review of the evidence by the Update Committee. RESULTS: Changes to previous recommendations include the addition of tbo-filgrastim and filgrastim-sndz, moderation of the recommendation regarding routine use of CSFs in older patients with diffuse aggressive lymphoma, and addition of recommendations against routine dose-dense chemotherapy in lymphoma and in favor of high-dose-intensity chemotherapy in urothelial cancer. The Update Committee did not address recommendations regarding use of CSFs in acute myeloid leukemia or myelodysplastic syndromes in adults. RECOMMENDATIONS: Prophylactic use of CSFs to reduce the risk of febrile neutropenia is warranted when the risk of febrile neutropenia is approximately 20% or higher and no other equally effective and safe regimen that does not require CSFs is available. Primary prophylaxis is recommended for the prevention of febrile neutropenia in patients who are at high risk on the basis of age, medical history, disease characteristics, and myelotoxicity of the chemotherapy regimen. Dose-dense regimens that require CSFs should only be used within an appropriately designed clinical trial or if supported by convincing efficacy data. Current recommendations for the management of patients exposed to lethal doses of total-body radiotherapy, but not doses high enough to lead to certain death as a result of injury to other organs, include the prompt administration of CSFs.