Patients after brain stroke are at a higher risk of developing cognitive dysfunctions. Clinical studies show that it is the cause of cognitive impairment in approximately two thirds of patients above 65 years of age. Deficits arising after stroke may include all areas of daily functioning. The factor that determines the type of clinical symptoms is the location and the area of brain damage. Cognitive impairment affects treatment and rehabilitation and, consequently, the quality of life. There are several neuropsychological tests and clinical trials, with different ranges of sensitivity, to measure cognitive function. Cognitive dysfunctions can affect many cognitive areas or their isolated aspects. The clinical course is often characterised by a mild form of cognitive impairment, or an advanced multisymptomatic form, such as vascular dementia. There is a need for general recommendations for the diagnosis and treatment of cognitive impairment in patients after stroke which would include healthy lifestyle and risk factors. The article presents the most important and most frequent cognitive dysfunctions that can arise after ischaemic stroke together with the clinical characteristics of symptoms and possibilities of their diagnosis. Also, the mutual influence of the basic mood and cognitive functioning is highlighted. In addition, the article describes the impact of key factors for cognitive functioning after stroke on prognosis. The clinical picture of cognitive impairment after stroke includes non-specific and specific symptoms. The non-specific symptoms are a response of the body to homoeostasis impairment by a sudden vascular incident. The characteristics of the specific symptoms depend on the location of organic damage.