Objective To investigate the clinical value of thyroid function tests in patients with acute myocardial infarction. Methods A retrospective analysis of serum thyroid hormone levels in 72 cases of acute myocardial infarction (AMI) patients and 30 healthy controls of retired workers were carried out. Results In the acute myocardial infarction group, 4 patients were associated with thyroid disease, 34 cases appeared to have euthyroid sick syndrome. As compared with the control group, 68 cases of patients in the acute myocardial infarction group had declined in serum TT3 with significant difference (P<0.001), and the levels of TT4 and FT3 were also declined with significantly difference (P <0.01). There was no significant difference with respect to the serum levels of FT4 and TSH (P> 0.05). Conclusion The thyroid function in patients with acute myocardial infarction should be routine detected in order to have a better treatment and prognosis.