The target of this survey carried out in Guadeloupe (F.W.I.) is to search for eventual relationship between leprosy forms and ethnic features--Made in people subjected to same environmental factors, such a study avoids usual bias of investigations on the epidemiological aspect of "racial" factors. The 1522 investigated patients have been divided into 2 categories: allergic paucibacillary (Mitsuda +), and anergic multibacillary (Mitsuda -) patients. -). Three parameters were studied: morphological type empirically determined according to cutaneous pigmentation; ABO blood groups; and Rhesus phenotype. The results bring to the fore: Significant linkage between clinical forms and morphotype: the dominant Caucasian morphological typed subjects, with integument poor in melanin, are more numerous among multibacillary patients. This might confirm high sensitiveness of Caucasians to leprosy. No significant linkage between clinical forms and ABO blood groups. Nevertheless, variations are found already reported in more homogeneous populations: predominance of A group in multibacillary patients, of B and O groups in paucibacillary patients. Significant linkage between clinical forms and Rhesus phenotype. But this link does not seem to be imputable to ethnic factors because clinical forms distribution is the same in ccDee sub-population (the most frequent in West Africa), and in ccddee subpopulation (quite frequent phenotype in West Europe). In fact, only the ccDEe phenotype sub-population is significantly different from all the others, because multibacillary forms are particularly frequent (49.3%) and strike evenly women and men in this sub-population.