The efficacy of a single dose of cefotiam, a cephalosporin of the second generation, as prophylaxis for postoperative infection was analyzed in a prospective randomized study of 129 patients undergoing cerebrospinal fluid shunting. The main focus of interest was the rate of shunt infection requiring operative shunt removal. Data were evaluated in the total group and subgroups formed for normal and high risk patients, respectively. The overall rate of shunt infection was 7.5% in the cefotiam group and 12.9% in the control group. In the high risk subgroup infection rate was 14.3% with and 26.3% without cefotiam as opposed to 4.3% and 6.9%, respectively, in the normal risk subgroup. Although our results do not reach statistical significance, there is a noticeable difference of infection rate between those patients who receive the antibiotic and those who do not. Therefore, we favor single dose antibiotic prophylaxis in shunting procedures.