Objectives:To determine the frequency of primary ventriculoperitoneal shunt infection among patients treated at neurosurgical centres of the Hospital Authority and to identify underlying risk factors.Methods: This multicentre historical cohort study included consecutive patients who underwent primary ventriculoperitoneal shunting at a Hospital Authority neurosurgery centre from 1 January 2009 to 31 December 2011. The primary endpoint was shunt infection, defined as: (1) the presence of cerebrospinal fluid or shunt hardware culture that yielded the pathogenic micro-organism with associated compatible symptoms and signs of central nervous system infection or shunt malfunction; or (2) surgical incision site infection requiring shunt reinsertion (even in the absence of positive culture); or (3) intraperitoneal pseudocyst formation (even in the absence of positive culture). Secondary endpoints were shunt malfunction, defined as unsatisfactory cerebrospinal fluid drainage that required shunt reinsertion, and 30-day mortality.Results: A primary ventriculoperitoneal shunt was inserted in 538 patients during the study period. The mean age of patients was 48 years (range, 13-88 years) with a male-to-female ratio of 1:1. Aneurysmal subarachnoid haemorrhage was the most common aetiology (n=169, 31%) followed by intracranial tumour (n=164, 30%), central nervous system infection (n=42, 8%), and traumatic brain injury (n=27, 5%). The mean operating time was 75 (standard deviation, 29) minutes. Shunt reinsertion and infection rates were 16% (n=87) and 7% (n=36), respectively. The most common cause for shunt reinsertion was malfunction followed by shunt infection. Independent predictors for shunt infection were: traumatic brain injury (adjusted Primary ventriculoperitoneal shunting outcomes: a multicentre clinical audit for shunt infection and its risk factorsNew knowledge added by this study • The local rate of infection in ventriculoperitoneal (VP) shunts meets international standards.• Vancomycin antibiotic prophylaxis is a risk factor for shunt infection and is a novel finding.• VP shunt inserted as an emergency procedure is the strongest risk factor for infection. Implications for clinical practice or policy• There is a need to review prophylactic vancomycin administration in terms of timing, dosage, and the need for its combination with another antibiotic.• Emergency VP shunting is not recommended. Shunts should be implanted whenever possible as an elective procedure.• A comprehensive local shunt surgery protocol to reduce the risk of shunt infection is recommended.