In an effort to reduce the incidence of postoperative wound infection, the recently proposed regimen of intravenous vancomycin and tobramycin and streptomycin irrigating solution was used in 878 neurosurgical operations. There were eight infections, for an infection rate of 0.9%. This infection rate was compared to the rate in the previously reported series using a sequential statistical analysis. The infection rate was found to be significantly greater than that previously reported. Controlled clinical trials will be required before the efficacy of antibiotic prophylaxis in clean neurosurgical procedures can be considered proven.