Introduction. One of the leading causes of death in Poland is stroke. Cardiogenic stroke is known to be one of the most important reasons for acute ischaemic stroke (AIS), comprising 25-30% of all AISs. Aim of study.Assessment of the prevalence of different risk factors of cardiogenic causes of AIS using transthoracic echocardiography (TTE) Material and methods. Transthoracic echocardiograms performed in patients with AIS admitted to a single neurological ward between October 2013 and September 2017 were analysed. Patients were assigned, based on the results of their TTE and their previous medical history of atrial fibrillation (AF), to one of three groups depending on the level of the risk of occurrence of cardiogenic causes of AIS. Ethical permission. According to Dz.U.2001, no. 126, 1381 no ethical permission was needed.Results. 663 patients with AIS were included in the study. Patients with high risk of cardiogenic cause of AIS: 26.7% (N = 177 patients [p]). Of these, 64.4% (114 p) were diagnosed with AF. 31.6% (56 p) with sinus rhythm during hospitalisation had a history of paroxysmal AF (PAF). In 11.9% (21 p) of the patients qualified to the high risk group, factors other than AF were found. Patients with moderate risk of cardiogenic cause of AIS: 10.1% (67 p). Patients with low risk of cardiogenic cause of AIS: 25.9% (172 p). Echocardiographic results led to a change in therapy in 1.21% of cases.Conclusions. 1. Transthoracic echocardiography performed routinely in all AIS patients affects the treatment in a very low percentage of cases. 2. The group that could benefit the most from TTE examination includes people without established indications for chronic anticoagulant therapy, in particular patients after myocardial infarction and people with additional clinical symptoms. 3. In patients with AIS, the diagnostic sensitivity of TTE in the detection of PFO is low. Young people with a cryptogenic ischaemic stroke should undergo a transoesophageal assessment.