Background Infection is a major complication following cerebral spinal fluid (CSF) diversion procedures for hydrocephalus. However, their pediatric risk factors for surgical site infection (SSI) are currently not well defined. Because SSI prevention bundle is increasingly introduced, the purpose of this study was to evaluate risk factors associated with SSIs following CSF diversion surgeries under SSI bundle at a single quaternary care pediatric hospital.Methods We performed a retrospective cohort study of patients undergoing CSF diversion procedures from 2017 to 2019. SSIs were identified prospectively through continuous surveillance. We performed univariate analyses to determine an association between SSIs and patient demographics, comorbidities and perioperative factors, with subsequent multivariate logistic regression analyses to identify independent risk factors for SSI.Results We identified a total of 561 CSF diversion procedures with an overall SSI rate of 3.6%. In univariate analyses, older age, number of previous shunt revisions and comorbid cardiac disease were significantly associated with SSI. In multivariate analyses, history of brain tumor (OR2.75, 95%CI 1.03-7.33, P=0.04) and cardiac comorbidities (OR9.47, 95%CI 2.15-41.73, P=0.003) were significantly associated with SSIs. When endoscopic third ventriculostomy was excluded, only cardiac disease was independently associated with SSI. Cardiac diseases associated with SSI included single ventricle disease with palliative repair and valvulopathy with underlying connective tissue diseases. Conclusion This study showed that comorbid conditions (cardiac disease, brain tumor) were more important than perioperative factors as risk factors for SSI in pediatric patients undergoing CSF diversion procedures. Further investigation is needed to define the mechanisms behind these associations.