Following intracerebral injection of labeled erythrocytes, lymphocytes and/or peritoneal macrophages, cervical and inguinal lymph nodes were subjected to histologic examination. Labeled cells of all cell types were found in the cervical lymph nodes, but they were not observed in the inguinal lymph nodes. No labeled cells were demonstrated in the lymph nodes following intravenous injection of cell suspensions. It is assumed that an efflux of cells occurs in the perineural spaces of the exiting nerve fibers. The anatomic relationships were discussed.