We evaluated polymorphonuclear leucocyte (PMN) chemotaxis and cortisol levels in cord blood from 15 healthy term infants delivered by caesarean section and from 15 healthy vaginally delivered term infants. Mean neutrophil chemotaxis was significantly higher in infants delivered by caesarean section (78.3 +/- 23.4 microns) than in vaginally delivered infants (57.8 +/- 16.6 microns; P = 0.01). Mean blood cortisol level was significantly lower in infants delivered by caesarean section (9.14 +/- 2.76 micrograms/dl) than in infants born by vaginal delivery (20.71 +/- 6.98 P = 0.0001). No relationship was found between PMN chemotaxis and blood cortisol level. The higher neutrophil chemotactic activity observed in infants delivered by caesarean section could be related to general maternal anaesthesia.