The authors made a review of the diagnostic difficulties in meningoencephalitis by the Criptococcus neoformans, in vivo, today easier by special methods such as China ink and culture in the CSF. From their diagnosed 14 cases, 2 have been treated by Amphotericin B. The first was a chronic case with acute episodes which were less severe when Amphotericin B was used. This case has been alive for 20 months. The second case was an acute one with clinical and spinal fluid normalization and has a follow-up of 11 months. In both cases Amphotericin was used intravenously (50 mg in 500 ml of a solution of glycose at 5%) in the first case 4 series and in the second case 2 series. There were no complications. The authors consider that the use of Amphotericin B has given those cases a better prognosis.