The article provides a review of cognitive impairment in oncology patients basing on the example of ovarian cancer women. Consecutive steps in the research for neuropsychological assessment of cancer patient with non-CNS tumors are demonstrated, including currently existing cognitive studies for oncogynecological patients. The suspected reasons for cognitive impairment at different treatment stages are being analyzed with the focus on cognitive dysfunction in the group of ovarian cancer patients. It is being discussed in the article that besides of the neurotoxic influence of chemo treatment, cognitive functions of the ovarian cancer patients can be impaired due to various other factors and that the subjective assessment of cognitive functioning does not correspond to the objective results of the neuropsychological assessment. It is stated in the article that at the moment there is no uniform methodological approach for neuropsychological assessment of ovarian cancer patients and multidisciplinary platform is required including the use of EEG, MRI and fMRI methods for precise evaluation of subtle cognitive impairments.