Although infrequent, Trypanosoma cruzi reactivation is possible among patients with HIV/AIDS infection that develop a tumor-like or granulomatous lesion in the CNS. We report the case of a 60 years old male patient with HIV /AIDS and low CD4 lymphocytes count with cerebellar symptoms and mild paresis, associated to supra and infratentorial hypodense lesions and positive serology tests both to T. gondii and Trypanosoma cruzi. Empirical therapy against toxoplasmosis was prescribed together with antiretroviral therapy but without a favorable response. Brain Chagas disease was confirmedby quantitative PCR in the CSF but he died despite nifurtimox treatment. Despite its rare occurrence, Chagas disease affectingthe CNS is possible among patients with HIV/AIDS infection. Epidemiological exposure, a positive Chagas serological test and the image pattern of brain lesions support the suspicion.  Diagnosis can be confirmedby molecular test in CSF samples, including new quantitative methods. Despite an adverse prognosis, specific therapy can be attempted besides antiretroviral treatment.