Forty-six episodes of cerebrospinal fluid shunt infections developed in 32 patients undergoing cerebrospinal fluid shunt operations during a 13-year period (1972 to 1984). The infection rate was 21%/operative procedure and 33%/patient. The shunt infection rate in revisions of infected shunts was 52%, a rate significantly larger than that in revisions of noninfected shunts (11%). Eight patients (25%) of the initially infected patients had more than one infectious episode. Predominating pathogens in patients who had shunt revisions included coagulase-negative staphylococci in 8 of 15 episodes (4 patients). Coagulase-negative staphylococci accounted for 28% and coagulase-positive staphylococci for 14% of the initial infectious episodes. Risk factors for development of shunt infection included age younger than 3 years, a previously infected shunt and surgery to revise the infected shunt. Therapy of infected shunts with antibiotics alone or with antibiotics plus an operative shunt revision resulted in similar success rates.