In the present research work absolute neutrophil count has been used as a criterion of effectiveness of filgrastim in the treatment of taxane induced neutropenia in patients with breast cancer treated on an outpatient basis at the Regional Institute of Neoplastic Diseases from Trujillo, Peru. We included the clinical records of 60 patients whose inclusion criteria included the development of neutropenia after receiving chemotherapy with paclitaxel or docetaxel, during the period October 2016 to October 2017. At the beginning of the treatment, the number was recorded of clinical history, sex, age, height, weight, clinical stage of cancer, chemotherapeutic schedule, dates of administration of chemotherapy, number of cycles programmed and received, as well as the value of absolute neutrophil count. At the control appointment 15 days after chemotherapy, or in some admission to the Emergency ...