Does iridology work? To answer this question, the following databases were searched: MEDLINE, EMBASE, and CISCOM (all from their inception to the end of 1998). In addition, other experts on complementary or alternative medicine were asked for further references, and professional societies of iridologists were addressed and invited to contribute material. Finally, my own files were searched. All bibliographies of articles thus obtained were scanned for further relevant publications. This search strategy resulted in 77 publications on the subject of iridology. Copies of all of these articles were obtained unless it was clear from the title that it did not pertain to an experimental study. Those published in English, German, French, Spanish, and Italian were read in full. Of those published in other languages, the English abstracts were read, and if they suggested a relevant investigation, translations of the full article were obtained.