T-cadhcrin functions as a suppressor gene, which is frequently inactivated by aberrant promoter methylation in several human cancers, but its methylation status in oral squamous cell carcinoma (OSCC) has been scarcely studied:Thus this study aimed at exploring the clinical significance and prognostic value of T-cadherin methylation in sera of patients with OSCC. Methylation-specific PCR (MSP) and bisulfate sequencing PCR (BSP) was performed to examine the methylation status of T-cadherin. Then, the associations between methylation status of T-cadherin and various clinicopathological variables or patient survival were investigated in 202 patients with OSCC and 68 controls. T-cadherin methylation was detected in 62 out of 202 (30.7%) patients with OSCC, and the methylation status of T-cadherin in corresponding tissues was confirmed by BSP. Methylation of T-cadherin was significantly associated with advanced tumor T-stage (p<0.001) and N-stage (p=0.003), positive lymphatic metastasis (p=0.004) and tumor recurrence (p=0.001). In addition, patients with methylation of T-cadherin had worse overall survival (p=0.018) and progression-free survival (p<0.001) than patients without, and methylation of T-cadherin in sera was an independent prognostic factor for worse overall survival (HR: 3.626, 95% CI: 1.112-9.624, p=0.007) and progression-free survival (HR: 4.201, 95% CI: 1.562-10.038, p<0.001) of patients with OSCC. These results demonstrated that methylation of T-cadherin was frequently detected in sera of patients with OSCC, which was associated with risk factors of poor outcomes, and may act as a potential independent prognostic marker for patients with OSCC.