BACKGROUND: Cerebrospinal fluid (CSF) shunt infection remains a major cause of morbidity and mortality in the treatment of hydrocephalus. Studies have demonstrated the efficacy of antibiotic-impregnated shunt (AIS) systems in reducing CSF shunt infections in pediatric patients. Fewer studies evaluate the efficacy of AIS systems in adult hydrocephalus. OBJECTIVE: To determine whether categorical conversion to AIS shunt systems reduced the incidence of shunt infection in adults. METHODS: All adult patients undergoing CSF shunt insertion over a 7-year period were retrospectively reviewed (2004-2009). In 2006, a categorical switch to AIS catheters was made. Before 2006, standard nonimpregnated shunt catheters were used. We retrospectively reviewed the first 250 cases of AIS catheter implantation and compared them with the immediately preceding 250 non-AIS cases to assess 1-year incidence of CSF shunt infection. RESULTS: Five hundred shunt surgeries were performed for normal-pressure hydrocephalus in 378 patients (76%), pseudotumor cerebri in 83 patients (17%), and various obstructive/communicating hydrocephalus etiologies in 40 patients (8%). All patients were followed for 12 months. The mean age was 60 ± 18 years. Baseline characteristics were similar between AIS (n = 250) and non-AIS (n = 250) cohorts. Overall, 13 patients (2.6%) experienced CSF shunt infection, occurring a mean of 2 ± 2 months postoperatively. Shunt infection incidence was decreased in AIS (1.2%) vs non-AIS (4.0%) cohorts (P = .0492). Staphylococcus epidermidis was the most common pathogen in AIS and non-AIS cohorts. Oxacillin resistance was not increased in the AIS cohort. CONCLUSION: Categorical conversion to AIS catheters was associated with a reduced incidence of shunt infection. AIS catheters may be a reliable instrument for decreasing perioperative shunt colonization and subsequent infection in adults with hydrocephalus.