Invasive fungal infections (IFI) are frequent causes of mortality after allogeneic stem-cell transplantation (SCT). A very important risk factor for IFI is the use of steroids. We used a risk-based chemoprevention in an open-labelled pilot study. All patients received oral fluconazole or itraconazole (200-400 mg day(-1)) during their neutropenic episode. Starting on day +30, patients receiving prednisone > or =30 mg day(-1) were switched to twice weekly Amphotericin-B-lipid-complex (ABLC) in a dose of 4 mg kg(-1). Patients receiving lower steroid doses continued on the fluconazole/itraconazole prophylaxis. Between 1999 and 2002, 100 patients were enrolled and followed for IFI for 1 year. Seven patients were started on therapeutic daily ABLC treatment before day +30 because of documented or suspected IFI; four had definite or probable aspergillosis, and two had candidaemia. Thirty patients did not need prophylactic ABLC; only one developed candidaemia. Sixty-three patients received ABLC prophylaxis for a median of 52 days (range: 1-289). Seven of these patients developed IFI; one definite and two probable cases of aspergillosis, one case of probable Trichosporon beigelii infection, and three cases of candidaemia. The twice weekly ABLC was well tolerated. This risk-based chemoprevention appears to be effective and might diminish the role of steroids as risk factor for IFI after allogeneic SCT. The relatively high incidence of early IFI suggests that additional prophylaxis for IFI may be indicated for poor-risk patients prior to day +30.