The impact of human enterovirus (HEV) and human rhinovirus (HRV) respiratory tract infections in adult patients with hematological malignancies has been infrequently reported. We retrospectively studied 31 patients with an upper or lower respiratory tract infection (URTI/LRTI) by HEV (n = 18) or HRV (n = 15). At onset, a LRTI was present in 6 (33%) and 2 (13%) episodes of HEV and HRV infections, respectively, with or without an URTI. Progression to LRTI (pneumonia) from prior URTI was seen in 1 (6%) and 2 (13%) HEV and HRV infections, respectively. The presence of lymphocytopenia (<0.5 × 109/l) was higher in LRTI by HEV: 4/5 (80%) versus 2/10 (20%) by HRV. Eight of 18 (44%) patients with immunosuppression versus 3/14 (21%) patients with no immunosuppression at the onset of respiratory infection developed a LRTI. Thirteen per cent of patients had associated respiratory infections from bacteria, aspergillus, or CMV. Pulmonary aspergillosis was diagnosed in 20% of HRV infections. Three of 11 patients (27%) with a LRTI died, but pulmonary copathogens were also involved in all cases. In conclusion, HEV and HRV can be associated with LRTI in immunocompromised patients, although their direct impact on mortality is uncertain. © 2007 Wiley-Liss, Inc.