Granulocyte colony-stimulating factors such as filgrastim (Neupogen, Amgen, Inc.) and pegfilgrastim (Neulasta, Amgen, Inc.) are frequently used in clinical practice for the prevention of chemotherapy-induced neutropenia and its potentially life-threatening complications. Due to its unique neutrophil-mediated clearance, pegfilgrastim can be administered once per chemotherapy cycle. Clinical trials have shown that a single, fixed subcutaneous dose of pegfilgrastim 6 mg is comparable in safety and efficacy to daily injections of filgrastim for decreasing the incidence of infection following myelosuppressive chemotherapy in patients with cancer. Postregistrational trials have been conducted to evaluate the use of pegfilgrastim with emerging dose-dense regimens, in myeloid cancers and for mobilisation and engraftment of autologous stem cells. Ongoing clinical trials continue to explore further potential uses for pegfilgrastim.