Postinflammatory hyperpigmentation (PIH) is a disorder of pigmentation that is a common presenting complaint, especially in individuals with skin of color. It is associated with a significant psychological burden and decrement of quality of life. Management options include photoprotection, topical lightening agents, and lasers and energy devices. Clinical trials of melasma report a diversity of outcomes, which often impedes synthesis of results across trials, or comparison of results associated with different treatment modalities. This protocol describes the design of a consensus process that would culminate in the development of a core set of outcomes to be assessed in all clinical trials for PIH. A long list of candidate outcomes will be developed through a systematic review, combined with semi-structured interviews with various stakeholders, including patients, scientists, regulators, and health care professionals. This long list of outcomes will be reviewed and refined by a steering committee. Then two rounds of Delphi surveys of patient and physician groups, respectively, will be used to cull the list, with provisional inclusion of those items deemed "important" by 70% of the respondents. A consensus meeting will be held virtually or in person to vote on these items, and also to consider any changes necessary before acceptance of a final core outcome set. Development of a core outcome set for PIH is expected to improve and standardize outcomes reporting in current and future clinical trials. This, in turn, may facilitate aggregation of research results and permit comparison of outcomes across multiple studies.