BACKGROUND Caesarean sections (CSs) are associated with a high infection risk. Surgical site infection (SSI) incidence is among the markers of effectiveness of infection prevention efforts. The aim of this study was to analyze risk factors for SSI, incidence, and microbiology in patients who underwent CS. METHODS The study was conducted during 2013-2015 using active infection surveillance in 5 Polish hospitals according to the European Centre for Disease Prevention and Control surveillance network known as HAI-Net. For each procedure, the following data were registered: age, American Society of Anesthesiologists score, procedure time, elective or emergency procedure, use of perioperative antibiotic prophylaxis, microbiology, the treatment used, and other information. RESULTS SSI incidence was 0.5% and significant differences were noted among hospitals (between 0.1% and 1.8%), for different American Society of Anesthesiologists scales (between 0.2% and 4.8%) and different values of standardized SSI risk index (between 0.0% and 0.8%). In 3.1% of procedures, with no antibiotic prophylaxis, SSI risk was significantly higher. Deep infections dominated: 61.5% with superficial infections in only approximately 30% of cases and 2.6% of infections were detected postdischarge without readmissions. CONCLUSIONS Results showed high incidence of SSI in Poland without perioperative antibiotic prophylaxis, and secondly, ineffective surveillance according to CS status, considering outpatient obstetric care. Without postdischarge surveillance, it is not possible to recognize the epidemiologic situation, and further, to set priorities and needs when it comes to infection prophylaxis, especially because such low incidence may indicate no need for improvement in infection control.