Herpes gestationis is a rare autoimmune disorder of pregnancy. Diagnosis may be suspected by the nature and localisation of the eruption and its recurrence. Only histologic examination of a skin biopsy with immunofluorescence revealing a linear deposit of C3 along the basement membrane confirms the diagnosis. Corticotherapy is the treatment of choice, local or general, depending on the severity of the symptoms. We report the observation of two pregnancies occurring in the same patient. The clinical and paraclinical manifestations of the first pregnancy did not recur in the second pregnancy. This constitutes an unusual case among the observations reported in the literature. Furthermore, we touch upon the immunological mechanisms of herpes gestationis.