The Cochrane Collaboration is an international nonprofit organization that conducts systematic reviews of healthcare interventions. The organization has recently reviewed all studies meeting designated criteria on interventions for rosacea. To be included in the review, trials had to be randomized controlled trials (RCTs) that met the methodological criteria of the reviewers and that were conducted in an adult patient population with moderate to severe rosacea. The electronic databases searched included The Cochrane Skin Group Specialised Trials Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, BIOSIS, and Science Citation Index. The reviewers tried to obtain details of unpublished and ongoing RCTs through correspondence with authors and pharmaceutical companies. After evaluating the included studies, the reviewers concluded there is evidence that topical metronidazole in 1% cream and 0.75% gel formulations and azelaic acid in 20% cream formulation are effective and safe. Furthermore, there is some evidence that oral metronidazole and tetracycline are effective. The reviewers also made suggestions about future rosacea research.