In the past 30 years it has been a great development in the unders-anding and therapy of obsessive-compulsive disorder. Adequate pharmaco- and cognitive-behavior therapies reduce the symptoms in 40-60% of patients, so a remarkable portion of patients still remains refractory to conventional treatment. Neurosurgery--with it's reversible and irreversible techniques--brought a breakthrough in the therapy of treatment refractory patients. In the present case, we represent a 3 months follow-up of an obsessive-compulsive pctient treated by deep brain stimulation. In our case, the stimulation target was the anterior limb of internal capsule. The clinical symptoms were measured by Y-BOCS. In addition various neuropsychological tests were used to monitor patient's executive functions before and 3 months after the deep brain stimulation. We found that obsessive-compu sive symptoms improved after three months of the stimulation. The neuropsychological tests showed improvement in some executive functions (e.g. fluency, set-shifting, decision making). On the other hand our results revealed severe neurocognitive--mainly attention skill--deficits in a treatment refractory obsessive-compulsive patient.