Family name Деменьтьев (Dementev 
, Деменьтьев 
, Dementiev 
) , in the world, is a rare last name. The cognomen Деменьтьев is habitual in Moldova, where it is quite a rare surname, Latvia, where it is a rare surname, and Russia. Not in comparison with a country's population, it is commonest in Russia, Moldova, and Germany. Very seldom, Деменьтьев is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Dementev | China, United States, Germany, Russia, Ukraine |
| Деменьтьев | Russia, Kazakhstan, Belarus |
| Dementiev | Moldova, Latvia, United States, Germany, Russia |