Despite antibiotics, antifungals and haematopoietic growth factors, infections remain a major threat to neutropenic patients. To determine the role of granulocyte transfusions (GTs) in anti-infective therapy during neutropenia, GT administration was randomized in 74 adults with haematological or malignant diseases, febrile neutropenia and pulmonary or soft-tissue infiltrates after conventional or high-dose chemotherapy, a majority of them after allo-SCT (n=39). Neutrophil reconstitution was equal in the treatment and control arm. GT toxicity was minimal. The probability of 28-day survival after randomization was >80% in both groups, and no effect of GT on survival until day 100 could be detected in patients with fungal (n=55), bacterial or unknown infection (n=17) and various levels of neutropenia (ANC <500 vs >500 x 10(6)/l). These findings can be attributed primarily to procedural obstacles, such as long delay from randomization to first GT, low cell content and slow sequence of GT, difficulties in randomizing a safe and potentially life-saving treatment in severely endangered individuals, and a large proportion of rapidly recovering patients in both arms. The requirement of another trial in a more specific patient population with daily transfusions of sufficient numbers of granulocytes to support or refute the empirically acknowledged benefits of GT is discussed.