Thyrotropin receptor (TSHR) antibody (TRAb) assays based on human or porcine TSHR which are coated to a solid phase are the most commonly used detection methods in clinical practice for patients with thyroid diseases. Yet the difference of the diagnostic values of the two TRAb assays is largely unclear. The aim of our present study was to evaluate the clinical perfomance of a solid phase porcine TRAb assay based on an ELISA technique (TRAb-porcine) and a human TRAb assay based on a chemiluminescence signal detection procedure (TRAb-human). Of 158 patients enrolled in the study, 84 suffered from Graves' disease (GD), 34 had Hashimoto's thyroiditis (HT) and 40 had euthyroid nodular thyroid disease (NTD) without signs of autoimmunity. TRAb measurements were performed according to the manufacturer's instructions. The mean values of TRAb titers detected by the TRAb-human and TRAb-porcine assays in patients with GD were 12.14+/-10.80 IU/L and 15.27+/-13.65 IU/L, respectively. TRAb were detected in 80 and 78 out of 84 GD patients by the TRAb-human and TRAb-porcine assay, respectively. The diagnostic sensitivity of the TRAb-human and TRAb-porcine immunoassay was 95.2 and 92.9% respectively, by 100% specificity of both methods. TRAb values in GD patients detected by the TRAb-human and TRAb-porcine assays were significantly correlated (r=0.929, p<0.0001). Our results indicate that the second generation TRAb-porcine assay based on solid phase technology had a slightly lower diagnostic sensitivity compared to the TRAb-human assay.