Background: AP for the prevention of peristomal wound infection is recommended before PEG but is not practiced universally. Results of randomized controlled trials (RCTs) of AP have produced conflicting results. Objectives: To ascertain if AP reduces the risk of peristomal wound infection and to quantify any effect by meta-analysis. To estimate the cost savings of routine AP using cost-minimization analysis. Methods: Fully recursive literature search for RCTs of AP in the prevention of wound infection following PEG. Homogeneity of RCTs assessed by Breslow-Day method. Pooling of RCTs and calculation of relative and absolute risk reduction (RRR, ARR) and number needed to treat (NNT). Decision analysis model and sensitivity analysis (DATA 3.5, TreeAge Inc.) to estimate cost benefits of routine AP before PEG. Results: 7 RCTs of AP without significant heterogeneity (P=0.28). Crude pooled rates of wound infection were 6.4% in 421 patients receiving AP and 23.9% in 356 controls; RRR=73%; ARR=17.5% (95% CI 12.5-22.5%); NNT = 5.7 (95% CI 4.4-8.0). Cost minimization analysis: The probabilities (range for sensitivity analysis) for stomal and systemic infection on AP were 7% (1-15) and 1%(0.1-5) respectively. The corresponding values on no prophylaxis (NP) were 24% (10-30) and 7% (1-15%), respectively. The pharmacy cost (range for sensitivity analysis) for a course of topical, oral and iv antibiotics to treat infection were $1 (0.5-5), $5 (1-25) and $ 60 (40-200), respectively and for single dose AP was $ 4 (1-10). Cost for one day of hospitalization was $ 968 (500-5000). The cost / patient of AP and NP were $ 87 and $ 461 respectively. AP was cheaper than NP for all ranges of cost and probabilities tested. Conclusions: AP is effective in preventing peristomal wound infections and should be the standard of care in patients who are not already receiving antibiotics. AP will result in a cost saving of $ 374 / patient.