The threshold for prophylactic platelet transfusions in patients with hypoplastic thrombopenia generally recommended in the standard literature is 20,000 platelets/microL. A more restrictive transfusion policy may be indicated in patients with chronic severe aplastic anemia (SAA) in need of long-term platelet support. We evaluated the feasibility and safety of a policy with low thresholds for prophylactic transfusions (</=5,000 platelets/microL in stable patients; 6,000 to 10,000 platelets/microL in cases with fever and/or hemorrhagic signs) combined with progressive lengthening of transfusion intervals (up to at least 7 days irrespective of the interim course of platelet counts). The study was based on a retrospective analysis of a total of 18,706 patient days with platelet counts </=10,000/microL in patients with chronic SAA treated (for more than 3 months) on an outpatient basis. Altogether, 1,135 platelet transfusions were given, 88% at counts </=10, 000/microL and 57% at counts </=5,000/microL. The mean transfusion interval was 10 days. During the period of observation, three major nonlethal bleeding complications occurred, which could be well controlled. We conclude that the restrictive policy with low transfusion thresholds and prolonged transfusion intervals proved feasible and safe in chronic SAA patients.