Primary amoebic meningoencephalitis due to free living amoeba, also called 'brain eating amoeba', Naegleria fowleri, was detected in retroviral disease patient of 40 years who has history of using well water. Patient was admitted with severe headache, fever intermittent, nausea, vomiting and slurring of speech. CT scan and MRI scan findings were normal. CSF examination showed increased protein, low sugar and predominant lymphocytes. CSF was negative for cryptococcal antigen but wet mount preparation showed highly motile free living amoeba Naegleria fowleri. Patient was put on Amphotericin B, Metronidazole, Rifampicin in addition to ART and ATT and other supportive medications. His headache was relieved and patient improved and was discharged on request. Earlier eight cases have been reported from India of which four cases survived the acute episode.