The use of trichloroacetic acid (TCA) as a periorbital and eyelid peel for skin rejuvenation is gaining significant acceptance among oculoplastic surgeons, dermatologists, and other surgery groups. In spite of the current enthusiasm, there remain potentially serious complications resulting from any periorbital peel. Cases of cicatricial ectropion have been reported in phenol-peeled patients, and lower eyelid ectropion has reportedly occurred in patients undergoing deep eyelid peel in conjunction with a blepharoplasty (1,2). To avoid this complication, it is necessary to better understand the depth of the wound produced by different strengths and combinations of peeling agents applied to living eyelid tissue and, more important, to determine the concentrations of TCA that are likely to lead to cicatricial ectropion when applied in a consistent fashion. We chose upper-eyelid skin because it is easier to obtain for histopathologic study than lower-eyelid skin and, in our experience, is more sensitive to hypertrophic changes after chemical peeling or carbon dioxide laser resurfacing. We applied TCA to the preseptal skin of 10 patients 48 h before standard upper-eyelid blepharoplasty. The acid was applied to produce a "frost," using varying concentrations of acid, ranging from 20 to 50%. The treated skin removed at the time of blepharoplasty was reviewed in a masked fashion by a dermatopathologist to determine the depth of necrosis. We found that superficial peels with necrosis involving 30% of the epidermis were produced by the lowest-concentration combination of TCA applied (20% followed by 0%). As the strength increased, so did the depth of peel. The combination of 50% followed by a second application of 50% produced the deepest peel, with necrosis into the papillary dermis. This finding would indicate that the chance of developing cicatricial ectropion with any of the tested combinations of TCA should be very remote.