Chemotherapy-induced neutropenia is not only a major risk factor for infection-related morbidity and mortality, but is also a significant dose-limiting toxicity in cancer treatment. Patients developing severe (grade 3/4) or febrile neutropenia (FN) during chemotherapy frequently receive dose reductions and/or delays to their chemotherapy. This may impact on the success of treatment, particularly when treatment intent is either curative or to prolong survival. The incidence of severe or FN can be reduced by prophylactic treatment with granulocyte-colony stimulating factors (G-CSFs), such as filgrastim, lenograstim or pegfilgrastim. However, the use of G-CSF prophylactic treatment varies widely in clinical practice, both in the timing of therapy and in the patients to whom it is offered. While several academic groups have produced evidence-based clinical practice guidelines in an effort to standardise and optimise the management of FN, there remains a need for generally applicable, European-focused guidelines. To this end, we undertook a systematic literature review and formulated recommendations for the use of G-CSF in adult cancer patients at risk of chemotherapy-induced FN. We recommend that patient-related adverse risk factors such as elderly age (>or=65 years), be evaluated in the overall assessment of FN risk prior to administering each cycle of chemotherapy. In addition, when using a chemotherapy regimen associated with FN in >20% patients, prophylactic G-CSF is recommended. When using a chemotherapy regimen associated with FN in 10-20% patients, particular attention should be given to patient-related risk factors that may increase the overall risk of FN. In situations where dose-dense or dose-intense chemotherapy strategies have survival benefits, prophylactic G-CSF support is recommended. Similarly, if reductions in chemotherapy dose intensity or density are known to be associated with a poor prognosis, primary G-CSF prophylaxis may be used to maintain chemotherapy. Finally, studies have shown that filgrastim, lenograstim and pegfilgrastim have clinical efficacy and we recommend the use of any of these agents to prevent FN and FN-related complications, where indicated.