Problem statement: Cryptococcosis neoformans is commonest central nervous system infection in individuals infected with HIV. Most of the patients infected with Cryptococcus neoformans present with headache and visual changes. Approach: A 28 year old woman presented to Emergency Department (ED) with a chief complaint of headache, fever and vomiting and developed seizures during the first hour of admission. Firstly, diagnosed as cryptococcal meningitis, then, because of having a low White Blood Cell count (WBC) and low Total Lymphocyte Count (TLC) she was checked for HIV Ab and P24 Ag. Results: A diagnosis of HIV was made then her family members were checked for HIV and they were also HIV positive. Patient was discharged with a two month course of Fluconazole and after completion of antifungal treatment, Antiretroviral Treatment (HAART) was started. Conclusion: This case indicated that Cryptococcosis neoformans may develop in Immune-deficient patients, so complete laboratory workup and high index of suspicion to HIV should be under diagnosis.