The α S1 casein gene is one of the lacto protein genes, which are involved in the milk synthesis. The objective of this study was to identify genotypes of B and E alleles at the locus α S1 casein in the Guéra and Sahel goat herds in Mali. These herds were located in the Regional Center of Agronomic Research and the Ségala village in Kayes, Mali. A total of 101 blood samples (53 for Guéra goat and 48 for Sahel goats) were collected and analysed. Alleles B and/or E, located on exon 19, of the α S1 casein gene were amplified using allele specific amplification polymerase chain reaction and analysed using 2 percent agarose gel electrophoresis. Results from this analysis identified three genotypes: BB, BE and EE with frequencies 0.77, 0.17 and 0.06 for the Guéra goats. However, only the BB genotype was identified in the Sahel goats. The frequencies of alleles B and E in the Guéra goats were 0.86 and 0.14, respectively, with an observed and expected heterozygotes of 0.08 and 0.12, respectively.