We performed a retrospective study in patients who underwent high-dose chemotherapy and auto-SCT because of haematological malignancies. Forty patients were treated with palifermin while 80 were controls selected after being matched for diagnosis and length of neutropenia. Patients treated with BEAM or BU-CY or THIO-CY (BEAM/BUS) displayed, after palifermin, a lower rate of severe oral mucositis (P=0.03). This beneficial effect of palifermin was not evident in the stratum of patients treated with high-dose melphalan (HD-PAM). After palifermin, we observed in the whole treated population a reduced rate of 'fever of unknown origin' (FUO, P=0.02) and of severe infections not related to Gram-positive bacteria (FUO, Gram-negative bacteremia or pneumonia) (P=0.003). This effect of palifermin on infections not related to Gram-positive bacteria was evident only in patients receiving BEAM/BUS (P=0.01) and not in patients treated with HD-PAM (P=0.11). Fibrinogen peak in plasma was found to be reduced after palifermin in the whole population (P=0.01) and in the stratum who received BEAM/BUS (P=0.02) but not in the stratum of HD-PAM. In conclusion, anti-infectious beneficial effects of palifermin are more evident in BEAM/BUS-treated patients and toward some types of infections. Reduction of fibrinogen level after palifermin suggests that this agent reduces not only the rate of infections but also their severity.