Introduction: Meningoencephalitis and meningitis have a broad differential diagnosis: Infections caused by entero-viruses, human HPV types 1-4, 5, and 6, paramyxovirus (mumps), measles virus, and adenoviruses are among the causes of T.B. Clinical signs of primary H.I.V. infection cause hyperthermia, exhaustion, cold and cough, migraine, nasal cavity inflammation, widespread allergy, lymphadenopathy, and digestive issues. 2 Up to 17% of individuals get aseptic meningitis, meningoencephalitis, and encephalitis, which could be related to a quicker course of treatment for the disease and complication. After the onset of the initial H.I.V. infection symptoms and all other symptoms have subsided, neurological symptoms may develop or show up to 3 months later. Respiratory failure is a reasonably typical presentation to the I.C.U. in HIV-infected individuals. Since the meningoencephalitis epidemic, the overall incidence of Pneumocystis jiroveci as a cause of respiratory failure has decreased. There is evidence that continuing or initiating HAART in critically sick H.I.V. patients is helpful and should be addressed following a multidisciplinary discussion. Conclusion: One instance of meningoencephalitis and two cases of meningitis caused by primary H.I.V. infection is discussed. Patients with H.I.V. frequently enter the I.C.U. Due to respiratory insufficiency. Since the AIDS crisis, Pneumocystis jirovecii has generally become less common as a cause of respiratory failure. There is proof that starting or maintaining HAART is suitable for H.I.V. patients who are critically sick, so this should be taken into consideration following a multidisciplinary discussion. A literature analysis was carried out because critical care professionals have significant moral and practical repercussions when selecting whether to assist HIV-infected patients in the I.C.U.