Significant late infectious complications after ASCT are uncommon. Patients with hematologic malignancies have a significantly increased risk of more serious infections and should be observed carefully. For risk patients with hematologic malignancies and possibly solid tumors, a strict PcP prophylaxis is required. Patients with relapsed lymphomas could possibly be treated preventively against zoster with low-dose aciclovir to reduce the extent of zoster disease. Each patient should be informed carefully that early signs of zoster require an effective zoster treatment as soon as possible.