From December 1999 to February 2001, the Microbiological and Gynaecological Science Department of the University of Catania has been involved in the collection of umbilical cord blood samples. Eight hundred and sixty-three cord blood units were collected and sent to Sciacca's UCB bank. Among them, 429 were collected from newborns delivered vaginally, while the remaining were collected from Caesarean sections. The aim of this study was to evaluate the difference between umbilical cord blood samples collected during a vaginal delivery and those from a Caesarean section. In particular, the blood volume collected and cord blood CD34+ stem cell count were considered. The method of blood collection consisted of puncturing the umbilical cord vein with an 18-gauge needle and withdrawing the blood into a sterile bag immediately after clamping and newborn assistance. The blood was collected when the placenta was still in utero and the indication to the kind of delivery was, independently of the study, according to obstetrical good practice. The results of the analysis showed that the cord blood volume and the number of CD34+ cells collected were similar for the two groups. The higher median volume of blood collected from infants delivered by Caesarean section seems mainly due to the different clamping time, rather than to the kind of delivery.