OBJECT: Systemic antibiotics and antibiotic-impregnated shunt (AIS) systems are often used to prevent shunt infection. The authors conducted a systematic review to evaluate its effectiveness of antibiotics in patients who underwent placement of intracranial ventricular shunts. METHODS: The authors searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, LILACS, and the meeting proceedings from the American Association of Neurological Surgeons and from the European Association of Neurosurgical Societies until June 2005. Randomized and quasi-randomized trials comparing the use of prophylactic antibiotics (either systemic or AIS systems) in intracranial ventricular shunt procedures with placebo or no antibiotics were included in the review. RESULTS: Seventeen trials involving 2134 patients were included. Results from the meta-analysis showed that the use of systemic antibiotic prophylaxis for internal shunts was associated with a decrease in shunt infection (odds ratio 0.51; 95% confidence interval 0.36-0.73). The authors found no significant differences between the subgroups evaluated in type of internal shunt (ventriculoperitoneal/ventriculoatrial), age, or duration of the administration of antibiotics. CONCLUSIONS: The authors found a benefit of systemic prophylactic antibiotics in preventing shunt infection, regardless of the patient's age and the type of internal shunt used. The benefit of its use after the first 24 hours postoperatively remains uncertain. Future trials should be conducted to evaluate the effectiveness of different regimens of systemic antibiotics rather than placebo, namely single preoperative dose versus multiple doses. It should also be mandatory to evaluate the effectiveness of systemic prophylactic antibiotics for external ventricular drains. Evidence suggests that antibiotic-impregnated catheters reduce the incidence of shunt infection, although more well-designed clinical trials are needed.