Cefpirome (CPO) is a new parenteral cephalosporin with a wide antibacterial spectrum. In order to explore the possibility of using CPO in late pregnancy, we studied its placental transfer in vitro in a model of human placenta infusion. Mother-to-foetus in vitro transfer of CPO is high, similar to that of amoxicillin, with a placental clearance index of 0.20. A pharmacokinetic simulation based upon this result and data from literature suggests that CPO concentrations in foetal blood and amniotic fluid should be appropriate for the treatment of severe materno-foetal infections in late pregnancy. These preliminary results need to be confirmed by in vivo pharmacokinetic and clinical studies before recommending the use of CPO in late pregnancy.