Background: The trace elements are essential micronutrients that have important physiological, metabolic, and homeostatic roles in the human being. Up till now the actually role and effect of the trace elements on myocardial metabolism specifically on congenital cyanotic heart disease is not entirely clear. Objective: This study aimed to detect the serum level of selected trace elements (zinc, copper and selenium), and evaluate its effect and relation in congenital cyanotic heart disease. Methodology: This study had enrolled upon 50 children, included 30 patients with congenital cyanotic heart disease and 20 age matched normal healthy children as control group. All groups were subjected to thorough clinical history, examination and specific cardiac investigation as well as detection of serum levels of zinc, copper and selenium. All results were statistical analyzed. Results: The current study revealed that a highly significant decrease in the serum level of both zinc and selenium (p<0.001 and p<0. 01), however serum copper level has non significant increase in congenial cyanotic heart disease, were (p>0.05). There was non significant correlation between the mean serum levels of trace elements and the hemodynamic parameters,. Also there were non significant correlations between the age and sex of the studied group and the mean serum levels of these trace elements (p>0.05). Conclusion: Congenital cyanotic heart disease were associated with a highly significant decrease in the mean serum selenium and zinc levels, when compared with control group and non significant increase the mean serum copper levels. Changes in these trace elements suggested to play an important role in the pathogenesis of myocardial damage in congenital cyanotic heart disease