This was a cross-sectional survey in which 80 children with malignancies were studied at the Kenyatta National Hospital to determine cardiac status before and during cancer therapy. An equal number of age and sex matched subjects admitted to the surgical wards for minor procedures was recruited as a comparison group. All the subjects underwent clinical cardiac assessment. Chest radiographs, electrocardiograms (ECG), echocardiograms, haemograms and renal function tests were also performed. Overall, 13 cases (16.3%) had abnormal cardiac findings compared to 7 (8%) in the comparison group (p=0.429). Sixteen, two and five subjects had abnormal velocity of circumferential fibre shortening, ejection fraction and pericardial effusion respectively. Three out of the five subjects with pericardial effusion were cancer patients who had not undergone treatment. Mitral valve prolapse with regurgitation was diagnosed in one cancer patient. Though not statistically significant, children with malignancies appear to have a higher frequency of acquired cardiac abnormalities than those without cancers. Since a larger proportion of the abnormalities occurred in cancer children before commencement of treatment, the pathology is more likely to have resulted from the malignancies than therapy. There was no evidence to suggest that cancer treatment contributed to cardiac morbidity. We recommend that all oncology patients undergo cardiac evaluation on admission.