A retrospective study was conducted on all cases of pemphigus vulgaris occurring on oral mucosal surfaces in the files of the Oral Pathology Laboratory at Temple University from 1974 to 1996. A total of 35 biopsies from 33 patients were reviewed, 25 female and eight male. Patient ages ranged from 27 to 79 years; the mean age was 56.5. The most common clinical complaint was of painful ulcers that failed to resolve within several weeks. Thirty patients had no known history of pemphigus, while in three patients a history of pemphigus was known. The most common clinical impression was that of mucous membrane pemphigoid, but the differential diagnosis included other vesiculoerosive conditions.