Pichler G, Pocivalnik M, Riedl R, et al. C reactive protein: impact on peripheral tissue oxygenation and perfusion in neonates (Arch Dis Child Fetal Neonatal Ed 2012;97:F444–8). The authors of this paper have asked us to point out that there is an error concerning the units in which C–reactive protein (CRP) is measured. The unit for CRP in the abstract is correct with mg/l. However, the unit for CRP in the body of the paper is not correct – it should also be mg/l (Methods, Results, table 1). In table 2 there should be no unit of CRP because there are no CRP levels mentioned.