SUMMARYFour cases of herpes gestationis are reported and the immunopathological findings in these patients described. Complement deposition at the basement membrane zone of the patients' peri‐bullous skin was seen in all patients, immunoglobulin deposition in two. A circulating factor capable of fixing complement on the basement membrane zone of normal human skin was present in three patients. These findings are discussed and compared with the immunopathological findings in bullous pemphigoi