The authors report the results of a randomized clinical trial of antibiotic prophylaxis for post-operative infection following breast reconstruction with the transverse rectus abdominis myocutaneous (TRAM) flap. The aim was to evaluate the efficacy and tolerability of short-term parenteral prophylaxis with teicoplanin; the endpoint of the study was the reduction of wound contamination assessed by microbiologic culture of drain fluid. From October 1990 to March 1992, 38 patients were recruited: 20 patients were included in the antibiotic prophylaxis arm (teicoplanin i.v. 400 mg one hour before operation and in the following 12 h plus 200 mg i.v. at 24 h after operation) and 18 patients in the control group. Analysis of drain fluid showed a higher contamination (15/18 = 83%) in the control group (Staphylococcus epidermides, Streptococcus alfa-emoliticus, Enterobacter aerogenes, Peptostreptococcus magnus) as compared to the prophylaxis arm with teicoplanin (2/20 = 10%) (Staphylococcus coagulase-negative) (p < 0.0001). Moreover, 11 patients in the control group suffered from fever > 37.5-degrees-C as compared to one patient in the antibiotic prophylaxis group (p < 0.0001); the post-operation stay was 13.3 +/- 4.3 and 9.0 +/- 1.6 in the control and antibiotic arm, respectively (p = 0.0002). There were no antibiotic related side effect in this study. These results seem to confirm the value of parenteral short-term antibiotic prophylaxis of post-operative infection in this type of '' clean '' operative procedure.