Treatment- and disease-related neutropenia are associated with a number of negative clinical effects such as febrile neutropenia, documented infection, hospitalisation for infection-related morbidity, infection-related mortality, and decreased ability to administer the planned chemotherapy dose on schedule. Reductions or delays in dosage have the ability to jeopardise the effectiveness of treatment by lowering response rates. Not only are clinical outcomes adversely affected, but these complications can have a negative influence on patient quality of life. Filgrastim is a haematopoietic growth factor that primarily acts to stimulate the proliferation and differentiation of neutrophil progenitor cells. Filgrastim is capable of reducing the incidence and severity of neutropenia and the complications that accompany it in patients with cancer or HIV infection. Although there are few data evaluating the effect of treatment with granulocyte colony-stimulating factor on quality of life, it is assumed that the benefits would be seen through both the reduction of treatment-related complications and the enhanced potential for long-term disease control. A new, longer-acting form of filgrastim is now available that has the potential to simplify the management of neutropenia and further improve patient quality of life by decreasing the number of necessary injections. Additional prospective controlled trials that contain quality-of-life issues as endpoints are needed.