Aim. Assessment of working memory and executive dysfunctions, as well as the intensity of depressive symptoms in hyperthyroid patients with Graves' disease, compared to healthy subjects. Material and methods. Thirty (30) patients with Graves' disease (20 female, 10 male), aged 18-55, participated in the study. The control group consisted of 31 healthy subjects, matched by age, gender and educational level with patients in the examined group. The assessment of working memory and executive functions was estimated by the Wisconsin Card Sorting Test and the N-back test. The intensity of depressive symptoms was assessed by Beck Depression Inventory. Results. Significant disturbances of working memory and executive functions were noted in hyperthyroid patients with Graves' disease in comparison to healthy subjects. Longer disease duration was associated with worse results in psychological tests, while higher educational level of the patient resulted in better test outcomes. In the group of patients with Graves' disease, 1/3rd of them presented with significant intensity of depression symptoms; additionally, the intensity of depression symptoms correlated with cognitive function impairments in the whole group of examined patients.