Neutropenia and subsequent infections are common events that limit treatment of non-small cell lung cancer (NSCLC). Granulocyte growth factors (G- and GM-CSF) have been introduced in clinical practice and their use has yielded a reduction of the infection risk related to chemotherapy and a dose increase of drug delivery. Randomized clinical trials have shown that granulocyte colony-stimulating factors and, more recently, the longer-acting pegylated granulocyte colony-stimulating factor (pegfilgrastim) effectively reduce the incidence and severity of neutropenia and of its complications. Recommendations for the use of haematopoietic colony-stimulating factors from the American Society of Clinical Oncology (ASCO) have been published in 1994 and updated in 1996, 1997 and 2000. Recently, moreover, National Comprehensive Cancer Network (NCCN) guidelines for the myeloid growth factors in cancer treatment make available. Chemotherapy-associated myelosuppression is a major limitation of anticancer therapy also in early stage, local advanced and metastatic NSCLC. Recently, dose-dense chemotherapy has been shown to improve the outcome in early stage breast cancer and non-Hodgkin's lymphoma. However, few randomized trials have been reported on chemotherapy with or without granulocyte growth factors as primary prophylaxis in NSCLC. Presently, there is no evidence for a benefit in response rate and survival from the use of granulocyte growth factors as support of chemotherapy, in particular, for locally advanced and metastatic NSCLC. In clinical practice, the role of granulocyte growth factors for NSCLC treatment should be limited following the guidelines. An appropriate use of granulocyte growth factors may reduce the overall cost of treatment and improve the quality of life, important aims in the treatment of patients with local advanced or metastatic NSCLC. In the future, we need to identify patients who can benefit from granulocyte growth factors for optimize the schedule and doses, in advanced disease and also, after the recent positive results of adjuvant chemotherapy, in early stages. This review summarizes the present knowledge on the use of granulocyte growth factors in NSCLC.