We utilized Medline to perform a systematic review of the literature to quantify the aetiology of cellulitis with intact skin. Of 808 patients with cellulitis, 127-129 (15.7-16.0%) patients had positive needle aspiration and/or punch biopsy cultures from intact skin. Of the patients with positive cultures, 65 (50.4-51.2%) had cultures positive for Staphylococcus aureus, 35 (27.1-27.6%) for group A streptococcus, and 35-37 (27.1-29.1%) for other pathogens. The most common aetiology of cellulitis with intact skin, when it can be determined, is S. aureus, outnumbering group A streptococcus by a ratio of nearly 2:1. Given the increasing incidence of community-associated methicillin-resistant S. aureus infections, our findings may have critical therapeutic implications.