Scleroderma is chronic inflammatory disease of connective tissue of unknown etiology. Classification into two forms: systemic and localized scleroderma depends on type of skin symptoms, kind of immunological disturbances and involvement of internal organs by the disease. Systemic scleroderma occurs mainly in adults. This form of scleroderma is rare in children, but there is significant disproportion between clinical symptoms and progressive organ dysfunction. The most often form in children is localized scleroderma, which is considered as a benign form of the disease. The aim of the study was evaluation of 12-lead resting ECG with QTc analysis in children with systemic and localized scleroderma. Two groups of children with systemic (n=20) and localized (n=20) sclerodermia were studied. Control group consisted of 20 healthy children. They had electrocardiographic examination in lying position. ECG analysis consisted of evaluation of rhythm, heart rate, incidence of arrhythmia, PR interval, QRS complex, QT and QTc interval (Bazzet formula). Upper limit of QTc normal value was 440 ms. Mean QRS axis, conduction disturbances, intraventricular blocks, left and right ventricle hypertrophy were evaluated according to standard criteria. Additionally pathological Q wave, abnormal R wave progression and changes of ST segment were studied. Results. Routine 12-lead ECG examination in children with systemic and localized scleroderma doesn’t reveal arrhythmia and atrioventricular conduction disturbances. Children with either systemic and localized scleroderma had significantly higher heart rate at rest and longer QTc intervals as compared with control group. Mean QTc interval values were significantly longer in two forms of scleroderma and was above 440ms in 23% of children with the disease. It implies its control during routine visits.