Abstract: Objective To investigate the predictive value of preoperative platelet-to-lymphocyte ratio (PLR) for lymph node metastasis (LNM) in medullary thyroid carcinoma (MTC) patients. Methods Sixty-three patients diagnosed with MTC in Chinese PLA General Hospital from January 2001 to June 2017 were included in our study. Receiver operating characteristic (ROC) analysis was performed to identify optimal PLR cut-off value, and the related influencing factors of LNM were screened using univariate and multivariate logistic regression analyses. Results The optimal cut-off value of the PLR for predicting LNM obtained from receiver operating characteristic curve analysis was 107.955, with sensitivity of 63.0% and specificity of 94.1%, and the area under the curve was 0.775. Multivariate analysis showed that extrathyroid extension (OR, 4.255; 95% CI, 1.158-15.640) and the PLR≥107.955(OR, 8.384; 95% CI, 1.934-36.353) were independent predictive factors of LNM. Conclusion Preoperative PLR is related to LNM in patients with medullary thyroid carcinoma. Furthermore, high value of PLR confers a high risk of LNM.