OBJECTIVE: Precordial distress is a common complaint in the pediatric population resulting from cardiac or non-cardiac diseases. The management approach and the prognosis of precordial distress vary with different causes. Therefore it is important to identify the causes of this complaint. This study examined serum cardiac troponin I (cTnI) levels and other clinical and laboratory parameters in children with this complaint to explore the value of cTnI in identifying the causes of childhood precordial distress. METHODS: The medical documents of 123 children with precordial distress, including the history, the findings of physical examination, electrocardiogram, ultrasonocardiography and myocardial perfusion imaging (MPI), serum creatine kinase MB isoenzyme (CK-MB) activity and cTnI concentrations, were analyzed retrospectively. cTnI concentrations were detected using enzyme immoassy. The relationship between myocardial perfusion and cTnI concentrations was evaluated by rank correlation analysis. RESULTS: A total of 81 patients (65.9%) were diagnosed with non-cardiac disease among 123 cases with precordial distress and all of them had normal cTnI concentrations. The cTnI concentrations were increased above normal in 17 cases, and low myocardial perfusion was found in 36 of 42 children with cardiac diseases. There was a linear correlation between cTnI levels and the severity of myocardial perfusion decrease (r=0.974, P<0.01). CONCLUSIONS: The majority of childhood precordial distress may be caused by non-cardiac disease. Measurement of cTnI combined with MPI can identify the cause of childhood precordial distress.