Purpose <p>To evaluate diagnostic performance of positron emission tomography/magnetic resonance imaging (PET/MR) using a multiparametric model for the detection of cervical lymph node metastasis in head and neck squamous cell carcinoma (HNSCC). </p> Methods <p>Preoperative PET/MR of 95 cervical lymph nodes from patients diagnosed with HNSCC were retrospectively evaluated. Parameters of diffusion weighted imaging (DWI), dynamic enhanced imaging (DCE) and stand-ardized uptake value (SUV) of the nodes were extracted, including ADC_mean, K_trans, V_e, K_ep, SUV_mean and SUV_max. Multivariable logistic regression analysis was used to develop the diagnostic model of lymph node metastasis. The diagnostic performance of the independent parameters and the combined diagnostic model were evaluated according to receiver operating characteristic (ROC) curve analysis. P values less than 0.05 were considered statistically significant. </p> Results <p>(1)30 metastatic and 65 benign lymph nodes with pathological diagnosis were involved. (2) There were significant differences of SUV_max, SUV_mean, K_trans and V_e between the groups with metastatic nodes and benign nodes. (3) Compared with independent parameters, PET/MR combined parameters had the highest diagnostic efficacy, with area under the ROC curve of 0.91 (<i>P</i> &lt; 0.001).</p> Conclusions <p>Combined diagnostic model base on multiparametric PET/MR could im-prove the diagnostic efficacy of cervical lymph node metastasis in HNSCC. </p>