Non-Hodgkin's lymphoma is primarily a disease of the elderly, with 61% of the new cases reported in patients 60 years old or older. Aggressive combination chemotherapy can cure some patients, but there are frequently treatment failures and overall survival is low. Retrospective studies have found that treatment with less than standard chemotherapy doses is associated with lower survival, and surveys of practice patterns have found that many patients, especially elderly ones, are treated with substandard regimens and doses. Neutropenia is the major dose-limiting toxicity of chemotherapy in patients with non-Hodgkin's lymphoma. First-cycle use of colony-stimulating factor (CSF) can reduce the incidence of neutropenia and its complications and help maintain the chemotherapy doses. Researchers have investigated risk factors in patients with non-Hodgkin's lymphoma to determine which patients are at highest risk for neutropenia and would benefit from targeted first-cycle CSF support. It has been shown in several studies that advanced age, poor performance status, and high chemotherapy dose intensity are risk factors. Other trials suggest that low serum albumin levels, elevated lactate dehydrogenase levels, bone marrow involvement, and high levels of soluble tumor necrosis factor receptor are also risk factors. Dose intensity has also been shown in many studies to be an important predictor of survival in patients with non-Hodgkin's lymphoma. Managing the toxicity of chemotherapy with CSF has facilitated the delivery of planned dose on time, as well as dose-intensified chemotherapy regimens. The promising results from recent clinical trials of dose-dense regimens with CSF support suggest that this could prove to be the best strategy for improving patient outcomes.