BACKGROUND: Cardiac Troponin I (cTnI) is known as a cardiac biomarker in determining the myocardial damage of diseases which affect the heart muscle. OBJECTIVES: This study aims to evaluate the serum cTnI concentration in Markhoz Breed goats suffering selenium (Se) deficiency and its correlation with electrocardiographic parameters, and activity of creatine kinase (CK) and aspartate aminotransferase (AST) enzymes, as well as to determine the diagnostic value of troponin in that disease. METHODS: Blood samples of 94 goat kids of Markhoz breed with the age less than one month were taken, serum analyzed for the assessment of cTnI, CK and AST, 2 ml blood was used for determination of selenium concentration. Electrocardiography was recorded from all kids by using base-apex lead. Kids were divided into two groups based on serum selenium concentration. RESULTS: The concentration of cTnI was significantly higher in deficient kids compared with the control group. Results indicated significant negative correlation between cTnI and selenium concentration. There was no significant correlation between cTnI and AST, CK in deficient kids. Results show no significant difference in concentration of AST, and CK enzymes for two group of deficient kids and control group. The presence of arrhythmia is significantly higher in deficient kids than control group. CONCLUSIONS: The results of this study showed that the measurement of serum cTnI concentration can be useful in diagnosis of kids suffering from Se deficiency. Also ECG can be used aiming at the diagnosis of arrhythmia in kids with Se deficiency.