Objective To find the clinical and histopathological predictive factors for lateral lymph node ( LN ) metastasis in thyroid papillary microcarcinoma( PTMC ).Methods From January 2007 to December 2010,141 patients with PTMC underwent central and lateral LN dissections were enrolled in the study.The data from the cases were analyzed retrospectively to determine the predictive factors for lateral LN metastasis.Results Among the aforementioned cases,37 cases ( 26.2％ ) were PTMC with the presence of multifocality,24 ( 16.9％ ) Hashimoto thyroiditis,84 ( 59.6％ ) central LN metastasis,56 ( 39.7％ ) lateral LN metastasis.Multifocality,central LN metastasis,underlying Hashimoto thyroiditis,and upper pole location were significantly related to lateral LN metastasis in univariate analysis( P＜0.05 ).These four factors were also found to be independent predictive factors for lateral LN metastasis in multivariate analysis( P＜0.05 ).9(6.4％ ) of there patients were found to show skip metastasis in which there was lateral LN metastasis but no central LN metastasis.The upper pole location was statistically significantly associated with skip metastasis.Conclusions Patients with multifocality,central LN metastasis,underlying Hashimoto thyroiditis,and upper pole location should be paid more attention to the status of lateral LN.Skip metastasis occurs in a minority of patients with PTMC.Even if there is no central LN metastasis,patients with upper pole lesion should be searched carefully for the lateral cervical LN metastasis.