ABSTRACT We report the case of a 73-year-old male patient with Alzheimer's disease who underwent 10-daily transcranial direct current stimulation (tDCS) sessions. tDCS was applied over the left dorsolateral prefrontal cortex as an adjuvant to the traditional treatment that the patient was receiving, which consisted of anticholinergic medication and cognitive training. The data were qualitatively analyzed and are presented in an analytic and structured form. The effects on cognitive performance were evaluated using the Alzheimer's Disease Assessment Scale-cognitive subscale as the primary outcome. Secondary outcomes were assessed with a set of tests consisting of the Neuropsychiatric Inventory, the Blessed Dementia Scale and the Disability Assessment for Dementia. The data obtained revealed that the application of tDCS had a stabilizing effect on overall patient cognitive function and led to improved performance on all the secondary outcome tests. These preliminary results indicate that tDCS is a potential adjuvant therapeutic tool for cognitive rehabilitation in Alzheimer's disease .