Aim. To analyze the data of magnetic resonance imaging (MRI) of the brain in its toxoplasmosis in HIV-infected patients. Subject and methods. The clinical picture of cerebral toxoplasmosis was studied in 207 patients aged 18-76 years with Stage 4B HIV infection concurrent with the disease. Brain MRI using an Obraz-1 low-field (0.12 T) MRI scanner (Russia) was carried out in 115 (55.5%) patients. This investigation was conducted in 74 (65%) treated patients over time. Results. Brain T2-weighted and FLAR MRI scans most frequently revealed higher-signal polymorphic foci and T1-weighted MRI scans showed lower-signal ones predominantly involving the white matter or white-grey matter border. Perifocal edema was often recorded. Intravenous gadolinium contrast study indicated that these foci accumulated the contrast agent around the periphery following the target patterns. Sixty-four (86.5%) patients were observed to have significant positive changes: reductions in the number and sizes of foci and the area of perifocal edema; in 29 patients, the inflammatory foci changed into cysts as a favorable outcome of necrotizing encephalitis. The foci resolved completely only in 7% of the patients. Conclusion. MRI is of great importance in intensive care, neurology, or neurosurgery units where patients with cerebral toxoplasmosis mimicking an acute cerebrovascular accident or a brain tumor are particularly frequently admitted to.