There have been very few well-conducted trials in melasma and this makes the process of comparing treatment outcome between trials difficult. The Pigmentary Disorders Academy has examined the issues relating to clinical trials on melasma, and has proposed recommendations on how they should be conducted. This covers all aspects including correct diagnosis of the condition, evaluation of efficacy and safety outcome, and overall clinical trial design. It is anticipated that the establishment of accepted guidelines on the conduct of clinical trials in melasma will greatly assist the dermatological community.