Objective. Preterm birth (PTB) remains a major cause of neonatal morbidity and mortality. The association between PTB and infection is clear. The purpose of this report is to present a focused review of information on the use of antibiotics to prevent PTB. Methods. We performed a search of the PubMed database restricted to clinical trials or meta-analyses published in English from 1990 through May 2011 using keywords “antibiotics or antimicrobials” and “preterm.” Results. The search yielded 67 abstracts for review. We selected 31 clinical trials () or meta-analysis () for further full-text review. Discussion of each eligible clinical trial, its specific inclusion criteria, antibiotic regimen used, and study results are presented. Overall, trials evaluating antibiotic treatment to prevent preterm birth have yielded mixed results regarding any benefit. Conclusion. Routine antibiotic prophylaxis is not recommended for prevention of preterm birth.