Our prospective and longitudinal study aimed to analyse the aetiologies, clinical features and prognostic of non viral lymphocytes meningitis (NVLM). We recruited 131 patients, 77 males (59%) and 54 females (41%) sex-ratio 1.4. The mean age was 35 years [15-67]. 117 patients were HIV positive (89%) and 14 (11%) were HIV negative. Feverish meningoencephalitis was present in 85% of cases, with 7 days for mean delay of admission into hospital. 80 germs were found in the C.S.F. 70 Cryptococcus neoformans, 4 Mycobacterium tuberculosis, 3 Streptococcus pneumoniae, 1 Candida albicans, 1 Neisseria meningitis and 1 Trypanosoma gambiense. 63 aetiologies were linked to lymphocytes meningitis by indirect deduction: 41 cases of tuberculous meningitis with lung X-ray anomalies and M. tuberculosis in sputum (11 times), 11 cases of cerebral malaria with Plasmodium falciparum in blood, 11 cases of cerebral toxoplasmosis by significant features with cerebral tomodensitometry. Letality was 53%, 35% of patients improved and 12% were lost to follow-up. Our study shows the difficulties in the management of the NVLM, due to the delay of diagnosis, particularly for tuberculous meningitis.