The distinct biology of haematological disorders as well as other age-related issues in adolescent and young adult (AYA) patients deserves unique psychological and medical attention. It emphasizes the necessity for a treatment approach taking into consideration their special needs. These include fertility considerations, survivorship issues, psychological support, adherence to treatment difficulties and other dilemmas and problems exclusive to this group of patients. AYA patients may usually better support intensive treatments and if possible should be referred to special centres and participate in clinical trials. In recent years the focus on AYA patients in oncology and hemato-oncology has increased. Still a distinct approach to these patients is an unmet need. This special issue tries to increase awareness for this group of patients as well as to cover the wide spectrum of hematological disorders that is pertinent to AYA patients who face special therapeutic challenges. This publication is of interest for physicians dealing with AYA, especially in the field of hematology and oncology, as well as paramedical staff including nurses, psychologists, social workers and pharmacists.