The Japanese guidelines for the proper use of granulocyte-colony stimulating factor(G-CSF)have been revised on the basis of the current international guidelines and latest evidence. The guidelines for primary and secondary prophylactic administration of G-CSF are clearly defined in the revised version. Primary prophylactic administration is recommended as per the incidence of febrile neutropenia(FN): it is highly recommended for patients with an FN rate>20%, but selectively recommended for patients with an FN rate<20%. Secondary prophylactic administration is recommended only for patients who should be maintained on a constant dose of G-CSF for curative purposes. The revised version aims to improve, not limit, the clinical use of G-CSF based on both patient- and evidence-oriented decisions in clinical practice.