Background. Cerebral toxoplasmosis (CT) is one of the most common cause of focal neurological defi cit in HIV/ AIDS group of patients. Timely diagnosis of CT and antiparasitic therapy contribute to decrease of lethal outcomes and disability. Aim. To study neurological manifestations, cognitive functions and neuron-specifi c enolase (NSE) concentration in cerebrospinal fluid (CSF), in HIV/AIDS patients with CT. Material and methods. The 35 patients (10 females and 25 males) from 28 to 50 years old with confirmed diagnosis of HIV/AIDS-associated CT were included in the investigation group. Neurological status, cognitive function and laboratory CSF changings had been studied in prospective investigation before and during the treatment with control points in the 1st and 10th days of the observation. Results. The method of neurological manifestation of CT evaluation had been developed and implemented in practice. The association between neurological defi cit severity (movement and sensory disorders), cognitive decline and increasing CSF concentration of NSE in HIV/AIDS-associated CT was determined that demonstrates the activity of encephalitic process. Conclusion. Dynamic evaluation of NSE concentration in CSF with clinical assessment of neurological manifestation in patients with HIV/AIDS-associated CT may be used for confirmation of specific antiparasitic treatment effectiveness and for increasing clinical criteria significance.