This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

A systematic review is undertaken to assess the relevant literature and to establish the effectiveness of antimicrobial prophylaxis in patients undergoing colorectal surgery for the prevention of surgical wound infection (SWI).

The review addresses the following questions:

1 Does antibiotic prophylaxis diminish the risk of SWI in colorectal surgery.
2 What spectrum of bacteria (aerobes or anaerobes) needs to be addressed by antibiotic choice.
3 What is the best timing of antibiotic administration, specifically, should antibiotics be continued into the post operative period.
4 What route of antibiotic administration (intravenous, oral or both) is most effective in preventing SWI.
5 Does any antibiotic choice exceed the efficacy of currently recommended gold standard prophylactic antibiotic therapy ‐ for definitions see 'Methods of the review'.