Objectives: To describe the frequency of acquired Aplastic Anemia (AA) in four main referral hospitals, as well as the treatment patterns of this disease in Peru. Methods: An observational, multicenter, retrospective phase for 2016, and prospective phase during 2017, was carried out in the Arzobispo Loayza, Cayetano Heredia, Edgardo Rebagliati Martins and Carlos Alberto Seguín Escobedo national hospitals. Results: 48 patients were recruited, 21 (43,8%) had severe anemia, 26 (54,2%) were not exposed to any toxic, but 6 (12,5%) were exposed to organophosphates. Twenty-five of forty-eight patients (52,1%) began treatment with the methylprednisolone + cyclosporine + anti-thymocyte globulin regimen (rabbit or horse). The median time from diagnos...