We conducted a survey of clinical trials to assess the scientific evidences presented for the practical use of dinitrochlorobenzene, squaric acid dibutylester, and diphencyprone in the treatment of alopecia areata. Twenty-six papers published between January 1977 and January 1988, in English, French, and Italian were selected. We used a standardized protocol of evaluation, which focused principally on the reporting of methods. Twelve papers were uncontrolled studies. Of the controlled studies, 11 had a self-controlled design, two studies involved the use of parallel concurrent controls, and seven were randomized trials. With regard to criteria for entry, follow-up schedules, and criteria for evaluation of response to treatment, the studies were scored generally poorly; therapeutic regimen, patients' characteristics, withdrawals, and description of side effects in these studies were rated more highly. In light of our results, further and better-designed studies are needed for acceptance of dinitrochlorobenzene, squaric acid dibutylester, and diphencyprone in current therapy.