Surveillance of surgical site infection (SSI) is an important infection control activity. The Caesarean section procedure was selected, as part of the Scottish Surveillance of Healthcare Associated Infection Programme, to monitor and report upon the incidence of SSI. Data were collected prospectively for 715 patients undergoing a Caesarean section procedure for 35 weeks during the latter months of 2002 and the first quarter of 2003. Of these, 80 (11.2%) patients developed an SSI, 57 (71%) of which were detected by postdischarge surveillance. Risk factors associated with infection were analysed. The choice of subcuticular suture rather than staples to close the surgical site was associated with a significantly lower incidence of infection (P=0.021). Obese women experienced significantly more infections than women with a normal body mass index (P=0.028). Dissemination of the surveillance results has made clinicians aware of the influence of body mass index and choice of skin closure in relation to SSI in this patient population. Analysis of these data has led to a review of local practice. The results also indicate the importance of postdischarge surveillance if SSIs are to be detected in this patient group. Continuous data collection and timely dissemination of the results are important factors acting as the catalyst for a review of practice.