Objective: To quantify the incidence, risk and associated factors that contribute to the development of Surgical Site Infection (SSI) in emergency Caesarean Section (CS). Design: A retrospective case-control study. Setting: An acute District General Hospital in England. Sample: 206 patients (101 SSI patients and 105 non-SSI patients) who had emergency CS between January-December 2017. Methods: Grade of surgeon, smoking status, pre-operative vaginal swab, diabetes status, age, body mass index (BMI), membrane rupture to delivery interval and length of surgery were recorded. Risk factors significantly associated with SSI were identified using simple and multiple logistic regression procedures. Results: BMI (kg/m2) was significantly associated with SSI occurrence and age (odds ratio (OR) 1.17; 95% confidence interval (CI) 1.11 to 1.24; p<0.001). Substantive non-significant associations were recorded between SSI, patient age and vaginal swab. Conclusion: This study identified BMI as the only significant risk factor from a range of patient-level factors for the development of an SSI in emergency CS, possibly due to the impact of excessive adipose tissue on the body’s immune system and reduced effectiveness of antibiotics. The importance of appropriate wound management including frequent wound cleaning, appropriate dressings and dressing change and education is highlighted. Improved guidelines and strategies for managing at-risk patients would enable clinicians to manage emergency CS patients better and reduce the risk of SSI development. Diabetes status, patient age and pre-op vaginal swab were not significantly associated with SSI in emergency CS. Future research on larger samples should be conducted to validate these findings.