Objective : The aim of this study is to analyze on the external ventricular drainage [EVD] related ventriculitis, especially on their risk factors, management, and prevention. Methods : From January 2003 to December 2005, a total of 174 EVD catheters were placed in 112 patients at our institution. Of these patients, EVD-related ventriculitis were developed in 15 cases. Clinical variables such as age, sex, prior clinical diagnosis, placement of EVD insertion, duration of EVD, total numbers of EVD per person, and outcome were analyzed in theses cases to verify the risk factors, causative agents and outcomes. Results : Fifteen cases of EVD related ventriculitis were noted presenting infection incidence of 13.39 % per patient and 8.62% per procedure. Of these, five patients died from sepsis, seven patients were recovered from infection but neurological complications remained and three patients were recovered without any complications. Microbes were obtained from cerebrospinal fluid only in six patients. Acinetobactoer baumanii was the most common pathogen in our study [4 cases]. Among the various risk factors, only the prior clinical diagnosis showed the statistical significance. Patients who underwent decompressive craniectomy after severe brain trauma showed unfavorable outcome because of possible contaminative environment compared with other cases. Conclusion : EVD is considered as a safe procedure with good control of intracranial pressure if meticulous care is provided for EVD procedure and maintenance. With regards to risk factors and prevention, the higher incidence and unfavorable outcome was seen especially in patients with severe head trauma. Thus, special attention is required in these clinical settings.