Infections are among the most frequent complications in patients with hematological malignancies and in those undergoing high-dose chemotherapy and autologous hematopoietic stem cell transplantation. A profound knowledge on the epidemiology, diagnostic approaches, treatment modalities, and prophylactic strategies is essential for the clinical management of these complications in patients who are often severely immunocompromised owing to their underlying diseases and, in particular, the intensive myelosuppressive chemo- and immunotherapy.This textbook provides a clinically oriented, compact, and up-to-date overview on infections in hematology patients and their management. The typical pathogens to be considered in different subgroups of patients are identified, and further aspects of the microbiological background are explored. Clinical, imaging, and laboratory-based diagnostic techniques are discussed, and therapeutic strategies appropriate to different situations are then presented, with due attention to the pitfalls, toxicities, and interactions that can arise during antimicrobial treatment. Strategies to prevent infection are also outlined, encompassing antimicrobial prophylaxis, isolation procedures, hospital hygiene, protective immunization, and the use of hematopoietic growth factors.