The authors report 23 cases of hereditary epidermolysis bullosa (EB). An attempt has been made to classify them. It was based only on the clinical and genetic criteria. The EB simplex has been found in 14 patients, 5 cases were of the Köbner type. The other 9 cases were of the Cockayne-Weber type. EB dystrophica was isolated in 9 cases, 7 cases of which were carriers of the Hallopeau-Siemens form, one case of the pretibial form and one case of Bart syndrome. The frequencies obtained are largely above the values reported in the literature.