Introduction: Serum (1-3)-beta-d-glucan (BDG) assay has been proposed as an adjunct for the rapid diagnosis of invasive fungal infection (IFI). However, false-positive results have been reported following transfusion of blood products in adults. Aims: To assess the relationship between blood product transfusion and elevated BDG in neonates. Method: Retrospective study including neonates 32 weeks, with no fungal colonization or infection, in whom BDG assay was performed for suspicion of IFI. Patients were classified in Transfusion (n=78) and No Transfusion (n=55) groups depending on whether or not they were transfused. Clinical, biochemical and microbiological characteristics were recorded. A BDG assay >80pg/mL was considered as positive. Statistical analyses: bivariate and multivariate logistic regression. Results (median, IQR): One hundred and thirty-three infants were included (gestational age 28.4 weeks, 26.9-30; birth weight 1000g, 847-1300). BDG was higher in the Transfusion group (170pg/mL, 65-317) than in the No Transfusion group (57pg/mL, 34-108; p<0.001). False-positive BDG assay results were associated with red blood cells (RBC) and fresh frozen plasma (FFP) transfusions. Conclusion: BDG is increased after RBC and FFP transfusions in neonates, leading to overdiagnosis of IFI. Fungal colonization status in peripheral sites and central cultures could help to reduce the risk of misdiagnosis.