The Gm, Am and Km immunoglobulin allotypes and ABO blood groups were studied in three groups of Tunisian Berbers . The results showed that the actual Berbers of Tunisia present certain heterogeneity and their ancestors were probably the first inhabitants of North Africa. Indeed, although their Gm-Am haplotypes are mainly Caucasoid, some of them are typically African. The group of Kesra village, the most Caucasoid, shows frequencies of Gm-Am haplotypes very close to those of South European populations, particularly the Spanish, who are probably of the same origin. The gene frequencies of the ABO groups in the three Berber groups were similar to those recorded in European populations with a relatively high frequency of the O genes typical of the Berbers .