The ERα gene has been intensively studied for more than a decade. During this long time, multiple promoters used in ERα expression have been discovered in several species. Although an already large body of literature describing various aspects of the regulation of ERα expression and utilization of different promoters is constantly growing, the inconsistent terminology used by individual authors makes the interpretation and comparison of data very difficult. Furthermore, completion of the human genome project now allows all known human ERα promoters to be placed on a physical map. This review describes promoters used in the generation of ERα transcripts in human and in other species and suggests a consistent nomenclature. The possible role of multiple promoters in the differential expression of ERα in tissues and during development is also discussed.