This single-centre, prospective randomized intervention study was conducted in a tertiary neonatal and paediatric intensive care unit in the Children's Hospital of Lucerne, Switzerland between June 1, 2005 and December 31, 2006. All term and near term infants with suspected early-onset sepsis were randomly assigned either to standard treatment based on conventional laboratory parameters (standard group) or to Procalcitonin-guided treatment (Procalcitonin-group). Minimum duration of antibiotic therapy was (48)-72 hours in the standard group, whereas in the Procalcitonin group antibiotic therapy was discontinued when two consecutive Procalcitonin values were below predefined age-adjusted cut-off values.