The present paper reports about description and new host record of caryophyllid cestode in a freshwater spiny eel, Mastacembelus armatus. A survey was conducted during autumn months of two consecutive years 2015 and 2016, from the border town of Manipur, Moreh. Many piscine cestodes were recovered during the course of investigation and out of which one was identified as the genus Lucknowia Gupta, 196. The present specimen shows morphological features viz., digit form to lance late scolex, longitudinal furrows in scolex, medullary testes, vitelline follicle in the medullary, post -testicular vitelline absent, ovarian follicular with inverted A- shaped and situated at the posterior extremity. Detailed are described and illustrated with figures and table.