Introduction: Hemolytic uremic syndrome is the most frequent cause of acute renal failure in children, commonly after gastrointestinal infections with E. coli or Salmonella, and it is characterized by progressive renal failure associated with microangiopathic hemolytic anemia and thrombocytopenia. Cardiac involvement is frequently encountered and can be potentially fatal in hemolytic uremic syndrome. It is usually determined by overhydration, hypertension, anemia, diselectrolytemia, acid-base disorders and tendency to form thrombi, and it consists in the following conditions: pericarditis, myocardial infarction, dilated cardiomyopathy, cardiac failure, and arrythmias. Objective: The aim of this study is to observe the incidence of cardiovascular complications in children with acute hemolytic uremic syndrome, underline which are the most useful tools in establishing an accurate diagnosis, and discover the treatment protocol that has the most powerful impact upon the cardiovascular manifestations. Materials and methods: We studied a number of 50 children who checked in the Nephrology Department of "M. S. Curie" Emergency Clinical Hospital in Bucharest, Romania, between January 2016 and August 2020. We performed the clinical examination of all patients as well as several paraclinical tests such as electrocardiogram, transthoracic echocardiography, arterial blood pressure monitorization, and vascular Doppler ultrasound. Patients included in the study were aged between five and 40 months. Discussion and results: The majority of these children were diagnosed with arterial hypertension and some of them with cardiac failure and profound venous thrombosis. Transthoracic echocardiography revealed pathological aspects such as left ventricular hypertrophy, diastolic dysfunction, systolic dysfunction of the left ventricle, mitral regurgitation, aortic regurgitation, and pericarditis. Cardiac ultrasound findings were reversible in the majority of patients, most of them being treated with ACE inhibitors (eventually in association with other antihypertensive drugs).