Infection disease due to Listeria monocytogenes, which is a ubiquitous positive Gram bacillus to the essentially alimentary transmission, listeriosis happens on patients presenting an immunodeficiency. The authors report the two first cases of listeriosis diagnosed at Hopital Principal de Dakar. The first case was observed on a 73 years old man, hospitalised for a feverish coma scored at 9 using Glasgow scale, with neither meningitis syndrome, nor sign of neurological localisation. The analysis of the RLC reveals a hypercytosis at 126 GB/mm3, with prevailing neutrophile polynuclears, a hyperproteinorachia at 3.2 g/l. The culture of the RLC was sterile but the blood culture showed the presence of L. monocytogenes. The other paraclinical tests has revealed a glycaemia at 2.45 g/l, an imporant hepatic cytolisis with ASAT at 13 N and ALAT at 20 N. The patient was also presenting a cerebromeningitis and hepatic listeriosis on a diabetic field. The second case was observed on a 58 years old patient admitted for headaches, fever and an important degradation of the general state with an emaciation of 17 kg in 5 months. The physical screening revealed a bad general state, a fever at 38 degrees 2 and was without other particularity. The analysis of the RLC showed a hyperproteinorachia at 1.35 g/l with neither hypercytosis nor germ at the culture. Haemoculture isolated Listeria monocytogenes. HIV serology was positive. CD4 were counted to 61/mm3. and the viral charge was at 110.000 copies / mm3. The patient was presenting a Listeria monocytogenes at meningo-encephalitis on HIV-1 field. stade B of the CDC classification. This ubiquitous anthropozoonosis should be searched through early haemocultures before antibiotherapy. in case of long lasting fever, endocarditis, meningo-encephalitis, localised infections on children. pregnant women, diabetic persons, and people infected with HIV and some others presenting immunity troubles.