Stroke in young individuals often has a cardiogenic etiology. The type of cardiac abnormality and the risk of potential embolism that is associated with it are different in comparison with the ones that occur in later decades of life. The diagnostic procedure in this group of patients should include comprehensive cardiological evaluation, including rhythm and structural abnormalities of the heart. In a significant proportion of young stroke patients, the etiological factor and the risk of recurrence are not established in spite of comprehensive evaluation. It is worth paying attention to abnormalities regarding the structure of the heart, which are treated as moderate- or low-risk abnormalities with undetermined real significance for stroke. The authors carried out a systematic analysis of cardiac diseases with established and potential significance for the development of stroke in young individuals. The results of the latest studies and experts' opinions were taken into account. The paper presents doubts arising in the course of diagnostic procedures, making the selection of appropriate methods of secondary prevention of stroke more difficult.