The results obtained in 80 patients hospitalized at the University of Obstetrics and Gynecology Clinic in Perugia for abdominal and vaginal hysterectomy are reported and evaluated in a prospective and randomized study of perioperative antibacterial prophylaxis. In the 75 patients available to study a single intravenous dose of 2 g cefotetan was compared with a triple dose of 1 g intravenous cephazolin. A reduction in the incidence of post-operative infections both in abdominal hysterectomy from 24% (cephazolin group) to 11.53% (cefotetan group) and in vaginal hysterectomy from 40% (cephazolin group) to 71.4% (cefotetan group) was noted. These results show that a single intravenous dose of 2 g cefotetan can be considered a valid therapeutic support for antibacterial prophylaxis. In addition the absence of alterations in the parameters considered (haematological, biochemical and urinary) points to the safety, effectiveness and non-toxicity of the drug.