Febrile neutropenia is a very common complication in patients with hematological malignancies receiving chemotherapy, and is associated with high morbidity and mortality. Infections caused by multidrug-resistant bacteria have become a therapeutic challenge in this high-risk patient population, since inadequate initial empirical treatment can seriously compromise prognosis. However, reducing antimicrobial exposure is one of the most significant cornerstones in the fight against resistance. The objective of these new guidelines is to update recommendations for the initial management of hematological patients who develop febrile neutropenia in this scenario of multidrug resistance. The two participating Societies (the Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica [Spanish Society of Infectious Diseases and Clinical Microbiology] and the Sociedad Española de Hematología y Hemoterapia [Spanish Society of Haematology and Haemotherapy]), designated a panel of experts in the field to provide evidence-based recommendations in response to common clinical questions. This document is primarily focused on bacterial infections. Other aspects related to opportunistic infections, such as those caused by fungi or other microorganisms, especially in hematopoietic stem cell transplantation, are also touched upon.