OBJECTIVE Indications of red blood cell transfusion in critically ill children are not very well determined. This study aims to describe red blood cells transfusion practice at the PICU of UNESP-Botucatu Medical School. METHODS Retrospective observational study of all patients who received transfusion during 2003. RESULTS Seventy five patients received transfusion and 105 indications were recorded. 53.3% of the patients were less than one year of age. Increased respiratory rate (75.2%), paleness (65.7%), and hypotension (51.4%) were the alterations more frequently recorded, before transfusion. Also, metabolic acidosis (68.08%) e and hipoxemia (63.8%) were very frequently observed. From 93 hemoglobin (Hb) values recorded, 54 (58.1%) varied from 7 to 10 g/dL and from 90 records of hematocrit (Ht) 66 (73.3%) varied from 21% to 30%. The main indications of the transfusion were anemia, in 75 children (71.4%), and active bleeding in 26 (24.7%). The mean value of Hb before transfusion was 7.82 ± 2.82 g/dL. Seven transfusions were indicated for patients with Hb levels higher than 10 g/dL (postoperative heart surgery and septic patients). CONCLUSIONS red blood cells transfusion is carefully prescribed at the PICU by using restrictive indications (Hb between 7 and 10 g/dL). Not always is possible to find out records of the Hb levels immediately before transfusion. Hence, a protocol to better prescribe red blood cell transfusion at the PICU was adopted.