Sickle cell anaemia (SCA), the commonest inherited haemoglobinopathy in Nigeria, is associated with highly variable clinical course and significant morbidity and mortality particularly in early childhood. The cardiac manifestations of SCA are age-dependent, and are a significant feature of the disease. Electrocardiographic (ECG) abnormalities have been reported in children with SCA but there is limited data on the ECG pattern in Nigerian children with this condition. The present study aimed at examining the relationship between ECG pattern and disease severity in Nigerian children with SCA, to determine the prevalence of ECG abnormalities as well as determine the relationship between ECG abnormalities with haemoglobin concentration and with sickle cell disease severity. This study, which was a cross-sectional descriptive study, was conducted in the University of Abuja Teaching Hospital, Gwagwalada, Abuja over a period of thirteen (13) months (May 2015 - May 2016). One hundred and forty SCA subjects in steady state aged one year to l7 years were consecutively recruited. Their socio-demographic characteristics and medical history were obtained using a study proforma and their ECGs recorded. The subjects’ disease severity statuses were categorized as mild, moderate or severe using a SCA disease severity index score. The information obtained was analyzed using the Statistical Package for Social Sciences (SPSS) version 16 software. The subjects studied consisted of 71 (50.7%) males, 69 (49.3%) females with mean age of 8.1±4.3 years. One hundred and nineteen (85%) of the subjects had at least one episode of crisis and 38 (24%) were transfused at least once in the one year preceding their enrolment.