In order to compare the clinical characteristics of familial and non-familial bullous lichen planus (BLP), the archival data of 36 BLP patients with positive family history and 21 BLP patients with negative family history diagnosed according to the clinical features and histopathology were collected in our department from 1956 to 2003. The clinical features were analyzed and compared. There were significant differences between familial and non-familial BLP in age of onset, duration of disease and extension of eruption (P<0.01). It was concluded that familial BLP appeared to differ from the non-familial form in its earlier age of onset, longer duration of the disease, more extensive eruption and more tendency to involve nails. Hereditary factors may play a role in the pathogenesis of familial BLP.